CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Cash flows from operating activities:
Net income (loss)	$ (4,012)	$ (10,936)
Adjustments to reconcile net (loss) income to net cash provided by (used in) operating activities:
Depreciation and amortization	4,330	9,424
Recovery from doubtful accounts	1,205	(48)
Stock-based compensation expense	4,835	3,743
Non-cash interest expense	3,433	5,966
Loss (gain) on extinguishment of debt	0	2,878
Unrealized foreign currency transaction losses (gains)	(112)	105
Provision for (benefit from) deferred taxes	383	43
Changes in operating assets and liabilities, net of effects from acquisitions:
Accounts receivable	18,783	9,168
Inventories	(484)	(1,149)
Prepaid expenses and other assets	(547)	(1,095)
Accounts payable	(22,003)	(167)
Accrued expenses, compensation and benefits and other liabilities	(4,057)	(6,106)
Income taxes payable	66	(6)
Deferred revenue and contract assets	(10,932)	(8,157)
Net cash provided by (used in) operating activities	(9,112)	3,663
Cash flows from investing activities:
Purchases of property and equipment	(3,212)	(3,576)
Net cash used in investing activities	(3,212)	(3,576)
Cash flows from financing activities:
Proceeds from revolving line of credit	22,000	0
Proceeds from long-term debt	7,800	79,289
Repayment of debt	(695)	(714)
Payments for repurchase of outstanding notes	(28,867)	(76,269)
Proceeds from the issuance of common stock under employee stock plans	0	309
Common stock repurchases for tax withholdings for net settlement of equity awards	(2,357)	(1,895)
Partial unwind capped call cash receipt	875	27
Payments for credit facility issuance costs	(289)	(5,979)
Net cash (used in) provided by financing activities	(1,533)	(5,232)
Effect of exchange rate changes on cash, cash equivalents and restricted cash	682	(3)
Net increase (decrease) in cash, cash equivalents and restricted cash	(13,175)	(5,148)
Cash, cash equivalents and restricted cash at beginning of period	72,575	68,094
Cash, cash equivalents and restricted cash at end of period	59,400	62,946
Supplemental Cash Flow Information [Abstract]
Cash and cash equivalents at end of period	55,662	50,955
Restricted cash	1,663	9,020
Restricted cash included in other long-term assets	2,075	2,971
Cash paid for income taxes	144	557
Cash paid for interest	$ 8,976	$ 5,163