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, 2016	Dec. 31, 2015	Dec. 31, 2014
Discontinued Operations And Disposal Groups [Abstract]
Revenue						$ 102,251	$ 585,866
Operating income						2,326	22,685
Gain on disposal						48,226	0
Income before income tax expense						50,553	21,625
Income tax benefit						(371)	(2,169)
Income from discontinued operations	$ 19,935	$ (1,235)	$ 358	$ 31,866	$ 0	$ 50,924	$ 23,794