Significant Accounting Policies - Schedule of Earnings Per Share (Detail) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Accounting Policies [Abstract]
Weighted average common shares outstanding—basic (in shares)	37,564	38,686	37,658	38,729
Dilutive effect of common stock options and awards (in shares)	149	202	121	183
Weighted average common shares outstanding—diluted (in shares)	37,713	38,888	37,779	38,912