4. Debt

Capital Lease Arrangements

Since 2013, the Company has entered into capital lease arrangements with an equipment manufacturer to finance acquisitions of computer equipment. These leases have effective annual interest rates ranging from 5.2% to 5.7%, and carry terms of 48 months. At the end of the lease periods, the Company has the option to purchase the underlying equipment at the estimated fair market value, or for a nominal amount in some cases. As of March 31, 2017 and December 31, 2016, the net book value of the equipment under these capital leases was $2,895 and $3,158, respectively, and the remaining principal balance payable was $3,162 and $3,411, respectively.

The maturities of all outstanding debt, consisting of the capital lease arrangements, as of March 31, 2017, are as follows:

Year ending
2017	$	853
2018		1,078
2019		886
2020		345
		3,162
Less:
Current portion		(1,029	)
Discount on long-term debt		(8	)
Non-current portion of debt	$	2,125

Revolving Credit Facility

In December 2016, the Company terminated its existing revolving credit facility with Silicon Valley Bank. No amounts were outstanding pursuant to the revolving credit facility at the date of termination.