Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Tax Disclosure [Abstract]
Current Income tax expense			$ 8,000
Income tax payable	$ 1,844		1,844
Income tax expense (benefit)	(2,133)	$ (9,770)	(32,372)	$ (9,770)
Income tax expense (benefit) in discontinued operations	$ (5,000)	$ 9,800	47,000	$ 9,800
Income tax provision in discontinued operations			224,300
Valuation allowance in discontinued operations			$ 177,400