Condensed Consolidated Statements of Stockholders' Equity - USD ($)  shares in Thousands, $ in Thousands  | 
Total  | 
Common Stock and Capital in Excess of Par Value, Shares  | 
Common Stock and Capital in Excess of Par Value, Amount  | 
Retained Earnings  | 
Accumulated Other Comprehensive Income (Loss)  | 
| Beginning balance (in shares) at Jun. 30, 2023 | 
 
 | 
136,750
 | 
 
 | 
 
 | 
 
 | 
| Beginning balance at Jun. 30, 2023 | 
$ 2,919,753
 | 
 
 | 
$ 2,107,663
 | 
$ 848,431
 | 
$ (36,341)
 | 
| Increase (Decrease) in Stockholders' Equity | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Net income | 
741,375
 | 
 
 | 
 
 | 
741,375
 | 
 
 | 
| Other comprehensive income (loss) | 
(13,097)
 | 
 
 | 
 
 | 
 
 | 
(13,097)
 | 
| Net issuance under employee stock plans (in shares) | 
 
 | 
173
 | 
 
 | 
 
 | 
 
 | 
| Net issuance under employee stock plans | 
(68,237)
 | 
 
 | 
(68,237)
 | 
 
 | 
 
 | 
| Repurchase of common stock (in shares) | 
 
 | 
(956)
 | 
 
 | 
 
 | 
 
 | 
| Repurchase of common stock | 
(459,093)
 | 
 
 | 
(14,722)
 | 
(444,371)
 | 
 
 | 
| Cash dividends and dividend equivalents declared | 
(179,256)
 | 
 
 | 
 
 | 
(179,256)
 | 
 
 | 
| Stock-based compensation expense | 
48,772
 | 
 
 | 
48,772
 | 
 
 | 
 
 | 
| Ending balance (in shares) at Sep. 30, 2023 | 
 
 | 
135,967
 | 
 
 | 
 
 | 
 
 | 
| Ending balance at Sep. 30, 2023 | 
2,990,217
 | 
 
 | 
2,073,476
 | 
966,179
 | 
(49,438)
 | 
| Beginning balance (in shares) at Jun. 30, 2023 | 
 
 | 
136,750
 | 
 
 | 
 
 | 
 
 | 
| Beginning balance at Jun. 30, 2023 | 
2,919,753
 | 
 
 | 
2,107,663
 | 
848,431
 | 
(36,341)
 | 
| Increase (Decrease) in Stockholders' Equity | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Net income | 
1,925,450
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Other comprehensive income (loss) | 
$ (5,179)
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Repurchase of common stock (in shares) | 
(2,392)
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Ending balance (in shares) at Mar. 31, 2024 | 
 
 | 
134,713
 | 
 
 | 
 
 | 
 
 | 
| Ending balance at Mar. 31, 2024 | 
$ 3,094,885
 | 
 
 | 
2,177,501
 | 
958,904
 | 
(41,520)
 | 
| Beginning balance (in shares) at Sep. 30, 2023 | 
 
 | 
135,967
 | 
 
 | 
 
 | 
 
 | 
| Beginning balance at Sep. 30, 2023 | 
2,990,217
 | 
 
 | 
2,073,476
 | 
966,179
 | 
(49,438)
 | 
| Increase (Decrease) in Stockholders' Equity | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Net income | 
582,534
 | 
 
 | 
 
 | 
582,534
 | 
 
 | 
| Other comprehensive income (loss) | 
17,174
 | 
 
 | 
 
 | 
 
 | 
17,174
 | 
| Net issuance under employee stock plans (in shares) | 
 
 | 
141
 | 
 
 | 
 
 | 
 
 | 
| Net issuance under employee stock plans | 
45,427
 | 
 
 | 
45,427
 | 
 
 | 
 
 | 
| Repurchase of common stock (in shares) | 
 
 | 
(848)
 | 
 
 | 
 
 | 
 
 | 
| Repurchase of common stock | 
(441,563)
 | 
 
 | 
(13,014)
 | 
(428,549)
 | 
 
 | 
| Cash dividends and dividend equivalents declared | 
(198,698)
 | 
 
 | 
 
 | 
(198,698)
 | 
 
 | 
| Stock-based compensation expense | 
48,620
 | 
 
 | 
48,620
 | 
 
 | 
 
 | 
| Ending balance (in shares) at Dec. 31, 2023 | 
 
 | 
135,260
 | 
 
 | 
 
 | 
 
 | 
| Ending balance at Dec. 31, 2023 | 
3,043,711
 | 
 
 | 
2,154,509
 | 
921,466
 | 
(32,264)
 | 
| Increase (Decrease) in Stockholders' Equity | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Net income | 
601,541
 | 
 
 | 
 
 | 
601,541
 | 
 
 | 
| Other comprehensive income (loss) | 
(9,256)
 | 
 
 | 
 
 | 
 
 | 
(9,256)
 | 
| Net issuance under employee stock plans (in shares) | 
 
 | 
41
 | 
 
 | 
 
 | 
 
 | 
| Net issuance under employee stock plans | 
$ (24,275)
 | 
 
 | 
(24,275)
 | 
 
 | 
 
 | 
| Repurchase of common stock (in shares) | 
(588)
 | 
(588)
 | 
 
 | 
 
 | 
 
 | 
| Repurchase of common stock | 
$ (375,696)
 | 
 
 | 
(9,415)
 | 
(366,281)
 | 
 
 | 
| Cash dividends and dividend equivalents declared | 
(197,822)
 | 
 
 | 
 
 | 
(197,822)
 | 
 
 | 
| Stock-based compensation expense | 
56,682
 | 
 
 | 
56,682
 | 
 
 | 
 
 | 
| Ending balance (in shares) at Mar. 31, 2024 | 
 
 | 
134,713
 | 
 
 | 
 
 | 
 
 | 
| Ending balance at Mar. 31, 2024 | 
3,094,885
 | 
 
 | 
2,177,501
 | 
958,904
 | 
(41,520)
 | 
| Beginning balance (in shares) at Jun. 30, 2024 | 
 
 | 
134,425
 | 
 
 | 
 
 | 
 
 | 
| Beginning balance at Jun. 30, 2024 | 
3,368,328
 | 
 
 | 
2,280,133
 | 
1,137,270
 | 
(49,075)
 | 
| Increase (Decrease) in Stockholders' Equity | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Net income | 
945,851
 | 
 
 | 
 
 | 
945,851
 | 
 
 | 
| Other comprehensive income (loss) | 
23,571
 | 
 
 | 
 
 | 
 
 | 
23,571
 | 
| Net issuance under employee stock plans (in shares) | 
 
 | 
134
 | 
 
 | 
 
 | 
 
 | 
| Net issuance under employee stock plans | 
(72,245)
 | 
 
 | 
(72,245)
 | 
 
 | 
 
 | 
| Repurchase of common stock (in shares) | 
 
 | 
(740)
 | 
 
 | 
 
 | 
 
 | 
| Repurchase of common stock | 
(570,936)
 | 
 
 | 
(12,536)
 | 
(558,400)
 | 
 
 | 
| Cash dividends and dividend equivalents declared | 
(196,555)
 | 
 
 | 
 
 | 
(196,555)
 | 
 
 | 
| Stock-based compensation expense | 
61,700
 | 
 
 | 
61,700
 | 
 
 | 
 
 | 
| Ending balance (in shares) at Sep. 30, 2024 | 
 
 | 
133,819
 | 
 
 | 
 
 | 
 
 | 
| Ending balance at Sep. 30, 2024 | 
3,559,714
 | 
 
 | 
2,257,052
 | 
1,328,166
 | 
(25,504)
 | 
| Beginning balance (in shares) at Jun. 30, 2024 | 
 
 | 
134,425
 | 
 
 | 
 
 | 
 
 | 
| Beginning balance at Jun. 30, 2024 | 
3,368,328
 | 
 
 | 
2,280,133
 | 
1,137,270
 | 
(49,075)
 | 
| Increase (Decrease) in Stockholders' Equity | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Net income | 
2,858,794
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Other comprehensive income (loss) | 
$ 6,442
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Repurchase of common stock (in shares) | 
(2,430)
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Repurchase of common stock | 
$ (1,738,612)
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Ending balance (in shares) at Mar. 31, 2025 | 
 
 | 
132,241
 | 
 
 | 
 
 | 
 
 | 
| Ending balance at Mar. 31, 2025 | 
4,004,739
 | 
 
 | 
2,401,317
 | 
1,646,055
 | 
(42,633)
 | 
| Beginning balance (in shares) at Sep. 30, 2024 | 
 
 | 
133,819
 | 
 
 | 
 
 | 
 
 | 
| Beginning balance at Sep. 30, 2024 | 
3,559,714
 | 
 
 | 
2,257,052
 | 
1,328,166
 | 
(25,504)
 | 
| Increase (Decrease) in Stockholders' Equity | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Net income | 
824,527
 | 
 
 | 
 
 | 
824,527
 | 
 
 | 
| Other comprehensive income (loss) | 
(20,882)
 | 
 
 | 
 
 | 
 
 | 
(20,882)
 | 
| Net issuance under employee stock plans (in shares) | 
 
 | 
104
 | 
 
 | 
 
 | 
 
 | 
| Net issuance under employee stock plans | 
43,931
 | 
 
 | 
43,931
 | 
 
 | 
 
 | 
| Repurchase of common stock (in shares) | 
 
 | 
(979)
 | 
 
 | 
 
 | 
 
 | 
| Repurchase of common stock | 
(655,973)
 | 
 
 | 
(16,478)
 | 
(639,495)
 | 
 
 | 
| Cash dividends and dividend equivalents declared | 
(228,609)
 | 
 
 | 
 
 | 
(228,609)
 | 
 
 | 
| Stock-based compensation expense | 
61,841
 | 
 
 | 
61,841
 | 
 
 | 
 
 | 
| Ending balance (in shares) at Dec. 31, 2024 | 
 
 | 
132,944
 | 
 
 | 
 
 | 
 
 | 
| Ending balance at Dec. 31, 2024 | 
3,584,549
 | 
 
 | 
2,346,346
 | 
1,284,589
 | 
(46,386)
 | 
| Increase (Decrease) in Stockholders' Equity | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Net income | 
1,088,416
 | 
 
 | 
 
 | 
1,088,416
 | 
 
 | 
| Other comprehensive income (loss) | 
3,753
 | 
 
 | 
 
 | 
 
 | 
3,753
 | 
| Net issuance under employee stock plans (in shares) | 
 
 | 
8
 | 
 
 | 
 
 | 
 
 | 
| Net issuance under employee stock plans | 
$ (2,680)
 | 
 
 | 
(2,680)
 | 
 
 | 
 
 | 
| Repurchase of common stock (in shares) | 
(711)
 | 
(711)
 | 
 
 | 
 
 | 
 
 | 
| Repurchase of common stock | 
$ (511,703)
 | 
 
 | 
(12,550)
 | 
(499,153)
 | 
 
 | 
| Cash dividends and dividend equivalents declared | 
(227,797)
 | 
 
 | 
 
 | 
(227,797)
 | 
 
 | 
| Stock-based compensation expense | 
70,201
 | 
 
 | 
70,201
 | 
 
 | 
 
 | 
| Ending balance (in shares) at Mar. 31, 2025 | 
 
 | 
132,241
 | 
 
 | 
 
 | 
 
 | 
| Ending balance at Mar. 31, 2025 | 
$ 4,004,739
 | 
 
 | 
$ 2,401,317
 | 
$ 1,646,055
 | 
$ (42,633)
 |