Summary of Significant Accounting Policies - Estimated Useful Lives of Property Plant and Equipment (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Property plant and equipment, gross	$ 7,657	$ 16,274
Less: accumulated depreciation	(4,541)	(5,542)
Property Plant And Equipment, Net	3,116	10,732
Building and Building Improvements
Property, Plant and Equipment [Line Items]
Property plant and equipment, gross	2,700	4,044
Property and Equipment
Property, Plant and Equipment [Line Items]
Property plant and equipment, gross	$ 4,957	$ 12,230
Minimum | Building and Building Improvements
Property, Plant and Equipment [Line Items]
Property plant and equipment, useful life	10 years
Minimum | Property and Equipment
Property, Plant and Equipment [Line Items]
Property plant and equipment, useful life	2 years
Maximum | Building and Building Improvements
Property, Plant and Equipment [Line Items]
Property plant and equipment, useful life	40 years
Maximum | Property and Equipment
Property, Plant and Equipment [Line Items]
Property plant and equipment, useful life	10 years