Shareholders' Equity - Schedule of Changes in Accumulated Other Comprehensive Income and Changes in Equity (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012
Schedule Of Shareholders Equity [Line Items]
Beginning Balance			$ 1,644,871	$ 1,529,611
Net income	71,629	47,489	118,081	102,044
Other comprehensive income (loss), net of tax	(5,180)	2,182	13,514	(1,267)
Treasury stock repurchases			(84,448)	(5,398)
Exercise of stock options, net of shares received			14,085	7,480
Share-based compensation, net of tax			16,152	7,621
Dividends ($per share)			(41,326)	(20,794)
Ending Balance	1,680,929	1,619,297	1,680,929	1,619,297
Preferred Stock [Member]
Schedule Of Shareholders Equity [Line Items]
Beginning Balance			0	0
Net income			0	0
Other comprehensive income (loss), net of tax			0	0
Treasury stock repurchases			0	0
Exercise of stock options, net of shares received			0	0
Share-based compensation, net of tax			0	0
Dividends ($per share)			0	0
Ending Balance	0	0	0	0
Common Stock [Member]
Schedule Of Shareholders Equity [Line Items]
Beginning Balance			970	961
Net income			0	0
Other comprehensive income (loss), net of tax			0	0
Treasury stock repurchases			0	0
Exercise of stock options, net of shares received			10	7
Share-based compensation, net of tax			0	0
Dividends ($per share)			0	0
Ending Balance	980	968	980	968
Additional Paid-in Capital [Member]
Schedule Of Shareholders Equity [Line Items]
Beginning Balance			971,748	943,971
Net income			0	0
Other comprehensive income (loss), net of tax			0	0
Treasury stock repurchases			0	0
Exercise of stock options, net of shares received			14,075	7,473
Share-based compensation, net of tax			16,152	7,621
Dividends ($per share)			0	0
Ending Balance	1,001,975	959,065	1,001,975	959,065
AOCI [Member]
Schedule Of Shareholders Equity [Line Items]
Beginning Balance			21,800	29,709
Net income			0	0
Other comprehensive income (loss), net of tax			13,514	(1,267)
Treasury stock repurchases			0	0
Exercise of stock options, net of shares received			0	0
Share-based compensation, net of tax			0	0
Dividends ($per share)			0	0
Ending Balance	35,314	28,442	35,314	28,442
Retained Earnings [Member]
Schedule Of Shareholders Equity [Line Items]
Beginning Balance			1,827,267	1,726,486
Net income			118,081	102,044
Other comprehensive income (loss), net of tax			0	0
Treasury stock repurchases			0	0
Exercise of stock options, net of shares received			0	0
Share-based compensation, net of tax			0	0
Dividends ($per share)			(41,326)	(20,794)
Ending Balance	1,904,022	1,807,736	1,904,022	1,807,736
Treasury Stock [Member]
Schedule Of Shareholders Equity [Line Items]
Beginning Balance			(1,176,914)	(1,171,516)
Net income			0	0
Other comprehensive income (loss), net of tax			0	0
Treasury stock repurchases			(84,448)	(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	$ (1,261,362)	$ (1,176,914)	$ (1,261,362)	$ (1,176,914)