Stock-Based Compensation - Information about Options Exercised (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended	9 Months Ended
	Mar. 31, 2014	Sep. 30, 2014	Sep. 30, 2013
Share Based Compensation Arrangement By Share Based Payment Award Options Activity [Abstract]
Options exercised	50,000	50,000	0
Total intrinsic value of exercised options		$ 1,970	$ 0
Fair value of vested stock options		17	17
Tax benefits realized		$ 603	$ 0