| Fair Value Measurements (Details) (USD $) | 1 Months Ended | 12 Months Ended | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Feb. 29, 2008 | Jun. 30, 2010 | Sep. 30, 2011 | Jun. 30, 2011 | |||||||||
| Fair Value Measurements [Abstract] | ||||||||||||
| Cash excluded from fair value measurement | $ 156,800,000 | $ 165,900,000 | ||||||||||
| Time deposits excluded from fair value measurement | 45,117,000 | [1] | 65,402,000 | [1] | ||||||||
| Auction Rate Securities, Contractual Maturity Date Range, Low | 20 | |||||||||||
| Auction Rate Securities, Contractual Maturity Date Range, High | 30 | |||||||||||
| Auction Failure | 48,200,000 | |||||||||||
| Available-for-sale Securities, Sold at Par | 16,800,000 | |||||||||||
| Total | ||||||||||||
| Fair Value Measurements | ||||||||||||
| Marketable securities | 1,898,230,000 | [2] | 1,807,277,000 | [3] | ||||||||
| Derivative assets | 845,000 | 1,970,000 | ||||||||||
| Executive Deferred Savings Plan | ||||||||||||
| EDSP money market and other | 4,967,000 | 1,806,000 | ||||||||||
| EDSP mutual funds | 110,923,000 | 126,227,000 | ||||||||||
| Executive Deferred Savings Plan | 115,890,000 | 128,033,000 | ||||||||||
| Total Financial Assets | 2,014,965,000 | [2] | 1,937,280,000 | [3] | ||||||||
| Derivative liabilities | (6,054,000) | (2,127,000) | ||||||||||
| Total Financial Liabilities | (6,054,000) | (2,127,000) | ||||||||||
| Total | Money market and other | ||||||||||||
| Fair Value Measurements | ||||||||||||
| Cash Equivalents | 578,442,000 | 481,770,000 | ||||||||||
| Total | US Treasury securities | ||||||||||||
| Fair Value Measurements | ||||||||||||
| Cash Equivalents | 4,400,000 | |||||||||||
| Marketable securities | 71,186,000 | 54,496,000 | ||||||||||
| Total | US Government agency securities | ||||||||||||
| Fair Value Measurements | ||||||||||||
| Cash Equivalents | 6,010,000 | |||||||||||
| Marketable securities | 344,132,000 | 314,173,000 | ||||||||||
| Total | Municipal securities | ||||||||||||
| Fair Value Measurements | ||||||||||||
| Marketable securities | 40,338,000 | 38,957,000 | ||||||||||
| Total | Corporate debt securities | ||||||||||||
| Fair Value Measurements | ||||||||||||
| Cash Equivalents | 21,982,000 | |||||||||||
| Marketable securities | 831,721,000 | 853,403,000 | ||||||||||
| Total | Sovereign securities | ||||||||||||
| Fair Value Measurements | ||||||||||||
| Marketable securities | 32,411,000 | 32,086,000 | ||||||||||
| Level 1 | ||||||||||||
| Fair Value Measurements | ||||||||||||
| Marketable securities | 999,948,000 | [2] | 869,045,000 | [3] | ||||||||
| Derivative assets | 0 | 0 | ||||||||||
| Executive Deferred Savings Plan | ||||||||||||
| EDSP money market and other | 4,967,000 | 1,806,000 | ||||||||||
| EDSP mutual funds | 85,709,000 | 95,971,000 | ||||||||||
| Executive Deferred Savings Plan | 90,676,000 | 97,777,000 | ||||||||||
| Total Financial Assets | 1,090,624,000 | [2] | 966,822,000 | [3] | ||||||||
| Derivative liabilities | 0 | 0 | ||||||||||
| Total Financial Liabilities | 0 | 0 | ||||||||||
| Level 1 | Money market and other | ||||||||||||
| Fair Value Measurements | ||||||||||||
| Cash Equivalents | 578,442,000 | 481,770,000 | ||||||||||
| Level 1 | US Treasury securities | ||||||||||||
| Fair Value Measurements | ||||||||||||
| Cash Equivalents | 0 | |||||||||||
| Marketable securities | 65,387,000 | 52,396,000 | ||||||||||
| Level 1 | US Government agency securities | ||||||||||||
| Fair Value Measurements | ||||||||||||
| Cash Equivalents | 6,010,000 | |||||||||||
| Marketable securities | 342,734,000 | 314,173,000 | ||||||||||
| Level 1 | Municipal securities | ||||||||||||
| Fair Value Measurements | ||||||||||||
| Marketable securities | 0 | 0 | ||||||||||
| Level 1 | Corporate debt securities | ||||||||||||
| Fair Value Measurements | ||||||||||||
| Cash Equivalents | 0 | |||||||||||
| Marketable securities | 0 | 0 | ||||||||||
| Level 1 | Sovereign securities | ||||||||||||
| Fair Value Measurements | ||||||||||||
| Marketable securities | 13,385,000 | 14,696,000 | ||||||||||
| Level 2 | ||||||||||||
| Fair Value Measurements | ||||||||||||
| Marketable securities | 898,282,000 | [2] | 938,232,000 | [3] | ||||||||
| Derivative assets | 845,000 | 1,970,000 | ||||||||||
| Executive Deferred Savings Plan | ||||||||||||
| EDSP money market and other | 0 | 0 | ||||||||||
| EDSP mutual funds | 25,214,000 | 30,256,000 | ||||||||||
| Executive Deferred Savings Plan | 25,214,000 | 30,256,000 | ||||||||||
| Total Financial Assets | 924,341,000 | [2] | 970,458,000 | [3] | ||||||||
| Derivative liabilities | (6,054,000) | (2,127,000) | ||||||||||
| Total Financial Liabilities | (6,054,000) | (2,127,000) | ||||||||||
| Level 2 | Money market and other | ||||||||||||
| Fair Value Measurements | ||||||||||||
| Cash Equivalents | 0 | 0 | ||||||||||
| Level 2 | US Treasury securities | ||||||||||||
| Fair Value Measurements | ||||||||||||
| Cash Equivalents | 4,400,000 | |||||||||||
| Marketable securities | 5,799,000 | 2,100,000 | ||||||||||
| Level 2 | US Government agency securities | ||||||||||||
| Fair Value Measurements | ||||||||||||
| Cash Equivalents | 0 | |||||||||||
| Marketable securities | 1,398,000 | 0 | ||||||||||
| Level 2 | Municipal securities | ||||||||||||
| Fair Value Measurements | ||||||||||||
| Marketable securities | 40,338,000 | 38,957,000 | ||||||||||
| Level 2 | Corporate debt securities | ||||||||||||
| Fair Value Measurements | ||||||||||||
| Cash Equivalents | 21,982,000 | |||||||||||
| Marketable securities | 831,721,000 | 853,403,000 | ||||||||||
| Level 2 | Sovereign securities | ||||||||||||
| Fair Value Measurements | ||||||||||||
| Marketable securities | $ 19,026,000 | $ 17,390,000 | ||||||||||
| 
 | ||||||||||||