Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax [Line Items]
Tax at federal statutory rate	35.00%	35.00%	35.00%
Deferred tax assets, valuation allowance	$ 516	$ 2,565
Decrease in the valuation allowance	2,100	6,300
State deferred tax assets	10,400	9,300
Unrecognized tax benefits for discontinued operations			$ 6,200
Recognized potential penalties and interest expense on uncertain tax positions	400	$ 300	$ 0
Federal NOL Carryforwards [Member]
Income Tax [Line Items]
NOL carryforwards	144,700
Canada [Member]
Income Tax [Line Items]
NOL carryforwards	$ 4,200