Income Taxes - Summary of Provision for Income Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
United States federal tax statutory rate, Amount									$ (50,352)	$ (42,671)	$ (16,311)
State taxes (net of deferred benefit), Amount									(4,663)	(2,487)	(1,121)
Non-deductible expenses, Amount									466	667	1,797
Change in fair market value of contingent consideration, Amount									777
Warrant remeasurement and financing costs, Amount									(32,348)
Research & Development Credits, Amount									(712)	(922)	(1,281)
Change in unrecognized tax benefits, Amount									142	186	256
Foreign tax rate differential, Amount									3,619	3,969	175
Goodwill impairment, Amount										20,816
Change in enacted tax rates and other, net, Amount									35,440	(1,069)	532
Change in valuation allowance, Amount									(20,365)	15,988	14,929
Income tax benefit	$ (963)	$ (738)	$ (741)	$ (858)	$ (816)	$ (1,070)	$ (992)	$ (2,645)	$ (3,300)	$ (5,523)	$ (1,024)
United States federal tax statutory rate, Percent of Pretax Earnings									34.00%	34.00%	34.00%
State taxes (net of deferred benefit), Percent of Pretax Earnings									3.10%	2.00%	2.30%
Non-deductible expenses, Percent of Pretax Earnings									(0.30%)	(0.50%)	(3.70%)
Change in fair market value of contingent consideration, Percent of Pretax Earnings									(0.50%)
Warrant remeasurement and financing costs, Percent of Pretax Earnings									(21.80%)
Research & Development Credits, Percent of Pretax Earnings									0.50%	0.70%	2.70%
Change in unrecognized tax benefits, Percent of Pretax Earnings									(0.10%)	(0.10%)	(0.50%)
Foreign tax rate differential, Percent of Pretax Earnings									(2.40%)	(3.20%)	(0.40%)
Goodwill impairment, Percent of Pretax Earnings									(0.00%)	(16.60%)
Change in enacted tax rates and other, net, Percent of Pretax Earnings									(24.10%)	0.80%	(1.20%)
Change in valuation allowance, Percent of Pretax Earnings									13.80%	(12.70%)	(31.10%)
Provision for income taxes, Percent of Pretax Earnings									2.20%	4.40%	2.10%