Shareholders' Equity - Schedule of Changes in Accumulated Other Comprehensive Income and Changes in Equity (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013	Mar. 31, 2012
Schedule Of Stockholders Equity [Line Items]
Beginning Balance			$ 1,529,611	$ 1,423,658
Net income	34,873	172,656	136,917	280,278
Comprehensive loss, net			(8,636)	(54,284)
Treasury stock repurchases			(5,398)
Exercise of stock options, net of shares received			10,322	8,843
Share-based compensation, net of tax			8,117	13,080
Dividends ($per share)			(30,984)	(15,858)
Ending Balance	1,639,949	1,655,717	1,639,949	1,655,717
Preferred Stock [Member]
Schedule Of Stockholders Equity [Line Items]
Beginning Balance			0	0
Net income			0	0
Comprehensive loss, net			0	0
Treasury stock repurchases			0
Exercise of stock options, net of shares received			0	0
Share-based compensation, net of tax			0	0
Dividends ($per share)			0	0
Ending Balance	0	0	0	0
Common Stock [Member]
Schedule Of Stockholders Equity [Line Items]
Beginning Balance			961	956
Net income			0	0
Comprehensive loss, net			0	0
Treasury stock repurchases			0
Exercise of stock options, net of shares received			8	5
Share-based compensation, net of tax			0	0
Dividends ($per share)			0	0
Ending Balance	969	961	969	961
Additional Paid-in Capital [Member]
Schedule Of Stockholders Equity [Line Items]
Beginning Balance			943,971	915,433
Net income			0	0
Comprehensive loss, net			0	0
Treasury stock repurchases			0
Exercise of stock options, net of shares received			10,314	8,838
Share-based compensation, net of tax			8,117	13,080
Dividends ($per share)			0	0
Ending Balance	962,402	937,351	962,402	937,351
AOCI [Member]
Schedule Of Stockholders Equity [Line Items]
Beginning Balance			29,709	136,733
Net income			0	0
Comprehensive loss, net			(8,636)	(54,284)
Treasury stock repurchases			0
Exercise of stock options, net of shares received			0	0
Share-based compensation, net of tax			0	0
Dividends ($per share)			0	0
Ending Balance	21,073	82,449	21,073	82,449
Retained Earnings [Member]
Schedule Of Stockholders Equity [Line Items]
Beginning Balance			1,726,486	1,418,106
Net income			136,917	280,278
Comprehensive loss, net			0	0
Treasury stock repurchases			0
Exercise of stock options, net of shares received			0	0
Share-based compensation, net of tax			0	0
Dividends ($per share)			(30,984)	(15,858)
Ending Balance	1,832,419	1,682,526	1,832,419	1,682,526
Treasury Stock [Member]
Schedule Of Stockholders Equity [Line Items]
Beginning Balance			(1,171,516)	(1,047,570)
Net income			0	0
Comprehensive loss, net			0	0
Treasury stock repurchases			(5,398)
Exercise of stock options, net of shares received			0	0
Share-based compensation, net of tax			0	0
Dividends ($per share)			0	0
Ending Balance	$ (1,176,914)	$ (1,047,570)	$ (1,176,914)	$ (1,047,570)