Discontinued Operations - Summary of Results of Discontinued Operations (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Discontinued Operations and Disposal Groups [Abstract]
Revenue									$ 102,251	$ 585,866	$ 573,959
Operating income									2,326	22,685	28,920
Gain on disposal									48,226
Income before income tax expense									50,553	21,625	29,019
Income tax expense (benefit)									(371)	(2,169)	8,908
Income from discontinued operations	$ 19,935	$ (1,235)	$ 358	$ 31,866	$ 13,374	$ 3,007	$ 3,232	$ 4,181	$ 50,924	$ 23,794	$ 20,111