Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended								6 Months Ended	9 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	Jun. 30, 2015	Sep. 30, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Income tax liabilities	$ 8,424				$ 9,778						$ 8,424	$ 9,778
Income tax benefit (expense)	4,424	$ (3,070)	$ 0	$ 0	(663)	$ (8,449)	$ (666)	$ 0	$ (666)	$ (9,115)	1,354	(9,778)	$ 0
Net operating loss carry-forwards	$ 269,000				$ 264,600						$ 269,000	$ 264,600
Operating loss carry-forwards expire year											2025
Operating loss carry-forwards expire year											2036