Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Income Taxes [Line Items]
Valuation allowance	$ 71,023,000	$ 70,478,000
Operating loss carryforwards, expiration end year	2036
Liabilities for unrecognized tax benefits	$ 2,900,000	3,100,000
Amount of unrecognized tax benefits, which, if recognized, would affect the tax rate	100,000	100,000
Penalties accrued related to unrecognized tax benefits	2,000	400
Interest accrued related to unrecognized tax benefits	4,000	3,000
Recognized total liability for penalties	13,000	15,000
Recognized total liability for interest	28,000	$ 24,000
Federal
Income Taxes [Line Items]
Operating loss carryforwards	103,300,000
State
Income Taxes [Line Items]
Operating loss carryforwards	35,600,000
Foreign
Income Taxes [Line Items]
Operating loss carryforwards	$ 118,200,000