Debt - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2017 USD ($) Installment	Dec. 31, 2016 USD ($)
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Revolving credit facility, amount outstanding		$ 0
Line of credit facility termination month and year	2016-12
Capital Lease for Acquisition of Computer Equipment [Member]
Line of Credit Facility [Line Items]
Number of monthly installments | Installment	48
Net book value of equipment under capital leases	$ 2,895,000	3,158,000
Remaining principal balance payable	$ 3,162,000	$ 3,411,000
Capital Lease for Acquisition of Computer Equipment [Member] | Minimum [Member]
Line of Credit Facility [Line Items]
Effective annual interest rate	5.20%
Capital Lease for Acquisition of Computer Equipment [Member] | Maximum [Member]
Line of Credit Facility [Line Items]
Effective annual interest rate	5.70%