Capital Stock - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
	Nov. 15, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Oct. 17, 2016	Mar. 17, 2015
Stockholders Equity Note [Line Items]
Common stock, shares authorized		200,000,000	200,000,000
Common Stock, par value		$ 0.01	$ 0.01
Preferred stock, shares authorized		10,000,000
Preferred stock, par value		$ 0.01
Stock Repurchase Program, Additional Repurchase Authorization					$ 300,000
Common stock repurchased, total purchase price		$ 277,306	$ 170,132	$ 24,666
Common stock purchased through modified dutch auction tender offer - in shares	5,308,905					2,766,354
Common stock purchased through modified dutch auction tender offer - price per share	$ 50.75					$ 58.50
Common stock purchased through modified dutch auction tender offer - total purchase price in dollars	$ 269,400					$ 161,800
Fees And Expenses Incurred Related To Modified Dutch Auction Tender Offer	$ 700					$ 700
Treasury Stock, Value, Acquired, Cost Method		277,306	$ 170,132	$ 24,666
Common stock repurchase, remaining authorized amount		$ 129,400
Treasury stock, shares		32,505,090	27,163,343
Activity related to restricted stock units vested [Member]
Stockholders Equity Note [Line Items]
Treasury shares issued		181,684	146,160	531,024
Average cost for restricted stock units		$ 6.30	$ 6.30	$ 6.30
Shares repurchased to satisfy employee withholding tax requirements resulting from certain restricted stock units becoming vested		67,061	50,841	234,440
Common stock repurchased, average cost		$ 51.15	$ 56.88	$ 48.87
Non-tender offer repurchase [Member]
Stockholders Equity Note [Line Items]
Repurchases of common stock		147,465	139,421	508,667
Common stock repurchased, total purchase price		$ 7,200	$ 7,600	$ 24,700
Treasury Stock Acquired, Average Cost Per Share		$ 48.81	$ 54.71	$ 48.47
Board of Director Members, Executive Officers, Related Family Foundations
Stockholders Equity Note [Line Items]
Repurchases of common stock	1,679,286
Treasury Stock Acquired, Average Cost Per Share	$ 50.75
Treasury Stock, Value, Acquired, Cost Method	$ 85,200