Stockholders' Equity - Additional Information (Detail) (USD $) In Millions, except Share data, unless otherwise specified	0 Months Ended
	Oct. 27, 2014	Oct. 28, 2013	Mar. 31, 2015	Dec. 31, 2014	Oct. 27, 2014	Oct. 28, 2013
Stockholders Equity Note [Line Items]
Special cash dividend declared, date	Oct. 27, 2014	Oct. 28, 2013
Special cash dividend record, date	Nov. 07, 2014	Nov. 08, 2013
Special cash dividend declared per share	$ 0.50	$ 0.35
Special cash dividend paid	$ 33.0	$ 23.0
Special cash dividend paid, date	Nov. 20, 2014	Jan. 02, 2014
Outstanding shares of common stock			65,543,000	65,303,000	65,298,472	64,987,854
Dividend equivalent paid per share on unvested shares of restricted stock outstanding on the dividend record date granted under the Company's 2006 Stock Option and Incentive Plan	$ 0.50	$ 0.35
Unvested shares of restricted stock on the dividend record date					655,499	676,281