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		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Numerator:
Income from continuing operations	$ 10,987	$ 9,589	$ 41,172	$ 35,777
Basic
Weighted average common shares outstanding	52,648	51,736	52,086	49,812
Diluted
Stock options	868	905	842	860
Restricted stock awards	189	204	251	260
Contingent shares	141	34	141	34
Convertible senior subordinated notes		1,566		1,319
Diluted weighted average common shares outstanding	53,846	54,445	53,320	52,285
Basic earnings per share from continuing operations	$ 0.21	$ 0.19	$ 0.79	$ 0.72
Diluted earnings per share from continuing operations	$ 0.20	$ 0.18	$ 0.77	$ 0.68