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Shareholders' Equity - Additional Information (Detail)	3 Months Ended			12 Months Ended
	Oct. 04, 2015 $ / shares	Jul. 05, 2015 $ / shares	Dec. 31, 2014 $ / shares	Dec. 31, 2015 USD ($) Vote $ / shares shares	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Nov. 01, 2015 USD ($)	Aug. 03, 2015 USD ($)	Apr. 29, 2014 USD ($)	Dec. 05, 2008 Right
Class of Stock [Line Items]
Authorized shares | shares				400,000
Preferred stock Par value (in dollars per share) | $ / shares				$ 0.01
Vote entitled for each common share outstanding | Vote				1
Number of preferred stock purchase right for dividend distribution | Right										1
Outstanding common share to be acquiring person				15.00%
Stock Repurchased During Period, Value				$ 126,351,000	$ 59,673,000	$ 47,908,000
Cash dividend declared per common share | $ / shares	$ 0.07	$ 0.07	$ 0.07
Payments of Dividends				$ 18,062,000
Repurchase Program 2014 [Member]
Class of Stock [Line Items]
total shares repurchased | shares				1,079,000
Stock Repurchased During Period, Shares | shares				895,000
Stock Repurchased During Period, Value				$ 42,415,000
Repurchase Program 2015 [Member]
Class of Stock [Line Items]
Repurchase of authorized common stock								$ 100,000,000
Stock Repurchased During Period, Shares | shares				2,311,000
Stock Repurchased During Period, Value				$ 83,936,000
Repurchase Program November 2015 [Member]
Class of Stock [Line Items]
Repurchase of authorized common stock							$ 100,000,000
Common Stock [Member] | Repurchase Program 2014 [Member]
Class of Stock [Line Items]
Repurchase of authorized common stock									$ 50,000,000
Repurchased shares, total cost				$ 50,000,000

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