Shareholders' Equity - Additional Information (Detail)	3 Months Ended							12 Months Ended
	Dec. 31, 2016 USD ($) Vote $ / shares shares	Oct. 02, 2016 $ / shares	Jul. 03, 2016 $ / shares	Apr. 03, 2016 $ / shares	Dec. 31, 2015 $ / shares shares	Oct. 04, 2015 $ / shares	Jul. 05, 2015 $ / shares	Dec. 31, 2016 USD ($) Vote $ / shares shares	Dec. 31, 2015 USD ($) shares	Dec. 31, 2014 USD ($)	Apr. 28, 2016 shares	Apr. 27, 2016 shares	Nov. 01, 2015 USD ($)	Aug. 03, 2015 USD ($)	Dec. 05, 2008 Right
Class of Stock [Line Items]
Authorized shares | shares	400,000							400,000
Preferred stock Par value (in dollars per share) | $ / shares	$ 0.01							$ 0.01
Common stock, shares authorized | shares	200,000,000				140,000,000			200,000,000	140,000,000		200,000,000	140,000,000
Vote entitled for each common share outstanding | Vote	1							1
Number of preferred stock purchase right for dividend distribution | Right															1
Outstanding common share to be acquiring person	15.00%							15.00%
Stock Repurchased During Period, Value								$ 47,149,000	$ 126,351,000	$ 59,673,000
Cash dividend declared per common share | $ / shares	$ 0.075	$ 0.075	$ 0.075	$ 0.07	$ 0.07	$ 0.07	$ 0.07
Payments of Dividends								$ 25,213,000
Repurchase Program 2014 [Member]
Class of Stock [Line Items]
total shares repurchased | shares								2,666,000
Stock Repurchased During Period, Shares | shares								355,000
Stock Repurchased During Period, Value								$ 16,064,000
Repurchase Program 2015 [Member]
Class of Stock [Line Items]
Repurchase of authorized common stock	$ 68,915,000							$ 68,915,000						$ 100,000,000
Stock Repurchased During Period, Shares | shares								539,000
Stock Repurchased During Period, Value								$ 31,085,000
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]
Repurchased shares, total cost								$ 100,000,000