Income Taxes - Additional Information (Detail) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)
Income Tax Disclosure [Abstract]
Current Income tax expense		$ 8,100
Income tax expense (benefit)	$ (30,239)	(30,239)
Income tax expense in discontinued operations	51,900	51,900
Accrued income tax provision	13,530	$ 13,530
Income tax provision in discontinued operations	223,300
Valuation allowance in discontinued operations	$ 171,400