Property and Equipment - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Accumulated depreciation	$ 93,860			$ 93,860		$ 96,700
Proceeds from sale of property and equipment				$ 3,035	$ 750
Asset Held for Sale [Member] | Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Proceeds from sale of property and equipment	$ 1,300	$ 1,200	$ 400
Gain (Loss) on fair value of assets less costs to sell		(300)
Other Current Assets [Member] | Asset Held for Sale [Member] | Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross						83,900
Accumulated depreciation						80,700
Fair value of assets less costs to sell		$ 2,900				$ 3,200