Earnings Per Share - Computation of Basic and Diluted Earnings Per Share for Continuing Operations (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Numerator:
Income from continuing operations	$ (565)	$ 10,987	$ 8,387	$ 21,798	$ (774)	$ 9,589	$ 6,685	$ 19,503	$ 40,607	$ 35,003	$ 30,414
Basic
Weighted average common shares outstanding	53,019	52,648	52,031	51,572	51,669	51,736	49,464	48,146	52,321	50,280	48,343
Diluted
Stock options									870	876	761
Restricted stock awards									261	277	293
Contingent shares									61	29	129
Convertible senior subordinated notes										1,231	1,961
Diluted weighted average common shares outstanding	53,019	53,846	53,079	52,745	51,669	54,445	52,024	51,385	53,513	52,693	51,487
Basic earnings per share from continuing operations	$ (0.01)	$ 0.21	$ 0.16	$ 0.42	$ (0.02)	$ 0.19	$ 0.14	$ 0.41	$ 0.78	$ 0.70	$ 0.63
Diluted earnings per share from continuing operations	$ (0.01)	$ 0.20	$ 0.16	$ 0.41	$ (0.02)	$ 0.18	$ 0.13	$ 0.38	$ 0.76	$ 0.66	$ 0.59