CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Cash flows from operating activities:
Net income (loss)	$ (5,671)	$ 1,792
Adjustments to reconcile net income (loss) from operations to net cash provided by (used in) operations:
Depreciation and amortization	2,862	2,747
Deferred tax expense (benefit)	(4)	(9)
Stock-based compensation	552	800
Accounts receivable, net	79	14,185
Inventories, net	(813)	535
Contract assets	2,578	(4,195)
Accounts payable	7,797	(3,360)
Income taxes payable	(3,491)	(3,012)
Accrued expenses	(5,560)	(821)
Deferred compensation	(126)	(1,258)
Deferred revenue	(455)	3,424
Other assets and liabilities	(1,485)	(1,102)
Net cash provided by (used in) operating activities	(3,737)	9,726
Cash flows from investing activities:
Purchase of short term investments	(4,475)
Maturities of short term investments	2,000	40,000
Additions to property and equipment	(176)	(2,296)
Net cash provided by (used in) investing activities	(2,651)	37,704
Cash flows from financing activities:
Tax payments for restricted stock issuances	(218)	(179)
Net cash used in financing activities	(218)	(179)
Effect of exchange rate changes on cash	(195)	572
Net increase (decrease) in cash	(6,801)	47,823
Cash, cash equivalents, and restricted cash, beginning of period	77,555	78,661
Cash, cash equivalents, and restricted cash, end of period	$ 70,754	$ 126,484