Capital Stock - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2018 USD ($) Vote $ / shares shares	Dec. 31, 2017 USD ($) $ / shares shares	Dec. 31, 2016 USD ($) shares	May 08, 2018 USD ($)	Apr. 30, 2018 USD ($)	Aug. 31, 2014 USD ($)
Components Of Common Stock [Line Items]
Authorized capital, shares (in shares) | shares	243,000,000
Common stock, par value (in dollars per share) | $ / shares	$ 0.01	$ 0.01
Common stock, shares authorized (in shares) | shares	240,000,000	240,000,000
Preferred stock, shares authorized (in shares) | shares	3,000,000	3,000,000
Common stock, voting rights description	The holders of common stock are entitled to one vote for each share of common stock on all matters submitted to a vote of the Company’s shareholders.
Common stock, votes per share | Vote	1
Stock repurchase program, authorized amount | $				$ 50,000,000		$ 50,000,000
Stock repurchased, average cost per share (in dollars per share) | $ / shares	$ 15.90
Acquisition of treasury stock | $	$ 22,456,000	$ 16,617,000	$ 5,144,000
Shares Paid for Tax Withholding for Share Based Compensation, Value | $	6,081,000
Amount remaining under repurchase authorization | $	$ 49,719,000				$ 46,900,000
Treasury Stock
Components Of Common Stock [Line Items]
Acquisition of treasury stock (in shares) | shares	1,412,000	1,536,000	572,000
Acquisition of treasury stock | $	$ 22,456,000	$ 16,617,000	$ 5,144,000
Seriesa Junior Participating Preferred
Components Of Common Stock [Line Items]
Preferred stock, shares authorized (in shares) | shares	240,000
Preferred stock, voting rights description	each share of Series A Junior Participating Preferred Stock would entitle the holder thereof to 1,000 votes on all matters submitted to a vote of the shareholders of the Company
Preferred stock, votes per share | Vote	1,000