Significant Accounting Policies - Schedule of Earnings Per Share (Detail) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Earnings Per Share [Abstract]
Weighted average common shares outstanding-basic	38,347	39,630	38,601	40,208
Dilutive effect of common stock options and awards	201	250	188	236
Weighted average common shares outstanding-diluted	38,548	39,880	38,789	40,444