| Derivative Instruments and Hedging Activities  - Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
| Mar. 31, 2016 | Mar. 31, 2015 | Mar. 31, 2016 | Mar. 31, 2015 | |
| Accumulated Other Comprehensive Income (Loss) | ||||
| Beginning balance | $ 5,719 | $ 12,125 | $ 7,110 | $ (20) | 
| Amount reclassified to income | 1,107 | (3,920) | 870 | (5,732) | 
| Net change in unrealized gains or losses | (2,798) | (1,309) | (3,952) | 12,648 | 
| Ending balance | $ 4,028 | $ 6,896 | $ 4,028 | $ 6,896 | 
| X | ||||||||||
| 
- Definition Accumulated Other Comprehensive Income (Loss), Cumulative Changes In Net Gain (Loss) From Cash Flow Hedges No definition available. 
 | 
| X | ||||||||||
| 
- Definition Accumulated Other Comprehensive Income [Roll Forward] No definition available. 
 | 
| X | ||||||||||
| 
- Definition The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
 | 
| X | ||||||||||
| 
- Definition The effective portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments that was recognized in other comprehensive income during the current period. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
 |