CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Cash flows from operating activities:
Net income (loss)	$ (7,771)	$ (16,577)
Adjustments to reconcile net (loss) income to net cash provided by (used in) operating activities:
Depreciation and amortization	11,469	15,905
Recovery from doubtful accounts	(156)	61
Stock-based compensation expense	5,788	4,331
Non-cash provision for restructuring	0	1,083
Non-cash interest expense	7,054	8,697
Loss (gain) on extinguishment of debt	2,878	0
Unrealized foreign currency transaction losses (gains)	237	(794)
Provision for (benefit from) deferred taxes	(886)	6
Changes in operating assets and liabilities, net of effects from acquisitions:
Accounts receivable	14,192	10,129
Inventories	788	294
Prepaid expenses and other assets	(3,526)	3,724
Accounts payable	(3,661)	3,467
Accrued expenses, compensation and benefits and other liabilities	(13,035)	(12,453)
Income taxes payable	372	423
Deferred revenue and contract assets	(12,631)	(22,544)
Net cash provided by (used in) operating activities	1,112	(4,248)
Cash flows from investing activities:
Purchases of property and equipment	(5,629)	(7,540)
Increase in other long-term assets	0	(25)
Net cash used in investing activities	(5,629)	(7,565)
Cash flows from financing activities:
Proceeds from long-term debt	79,286	22,688
Repayment of debt	(1,113)	(7,808)
Payments for repurchase of outstanding notes	(76,269)	0
Proceeds from the issuance of common stock under employee stock plans	309	266
Common stock repurchases for tax withholdings for net settlement of equity awards	(3,444)	(957)
Partial unwind capped call cash receipt	27	0
Payments for credit facility issuance costs	(5,979)	0
Net cash (used in) provided by financing activities	(7,183)	14,189
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(615)	(358)
Net increase (decrease) in cash, cash equivalents and restricted cash	(12,315)	2,018
Cash, cash equivalents and restricted cash at beginning of period	68,094	60,433
Cash, cash equivalents and restricted cash at end of period	55,779	62,451
Supplemental Cash Flow Information [Abstract]
Cash and cash equivalents at end of period	52,289	50,460
Restricted cash	1,664	8,500
Restricted cash included in other long-term assets	1,826	3,491
Cash paid (refunded) for income taxes	941	(2,268)
Cash paid for interest	$ 7,780	$ 9,024