Components of Income Tax Expense (Benefit) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Current income tax expense (benefit):
Foreign	$ 92	$ 70	$ 205	$ 161
U.S. Federal		(2,657)		(1,547)
Total current income tax expense (benefit)	92	(2,587)	205	(1,386)
Deferred income tax expense (benefit):
U.S. Federal	(6,395)	1,242	(11,680)	(3,515)
Total deferred income tax expense (benefit)	(6,395)	1,242	(11,680)	(3,515)
Actual tax on continuing operations	$ (6,303)	$ (1,345)	$ (11,475)	$ (4,901)