Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net (loss) income	$ (3,614)	$ (10,075)	$ (76,683)	$ 15,869
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Depreciation and amortization		12,328	12,988	13,390
Stock-based compensation expense		6,281	5,302	6,820
Deferred income taxes		(879)	(4,604)	4,073
Change in fair value of contingent consideration liability		0	0	677
Goodwill impairment		0	46,319	0
Intangible and other asset impairments		0	18,121	0
Bad debt provision		1,068	3,601	454
Contract implementation cost amortization		300	433	0
Change in fair value of warrant		2,233	0	0
Change in fair value of embedded derivative		(176)	0	0
Unrealized foreign exchange loss		834	0	0
Other operating activities, net		1,150	255	210
Changes in assets and liabilities:
Accounts receivable and unbilled revenue	(21,488)	(12,254)	4,470	(41,871)
Inventories	(8,913)	20,980	(16,039)	(4,245)
Prepaid expenses and other assets	(28,985)	(6,529)	2,120	(13,882)
Accounts payable	12,078	(15,634)	21,585	18,096
Accrued expenses and other liabilities	23,868	22,843	5,190	12,107
Net cash provided by operating activities	(9,655)	22,470	23,058	11,698
Cash flows from investing activities:
Purchases of property and equipment	(10,135)	(13,378)	(11,263)	(12,483)
Payments for acquisitions, net of cash acquired		(721)	0	0
Proceeds from sale of property and equipment		0	122	0
Net cash used in investing activities	(10,525)	(14,099)	(11,141)	(12,483)
Cash flows from financing activities:
Repayments of net short-term secured borrowings		(833)	(1,525)
Proceeds from net short-term secured borrowings				20,709
Repurchases of common stock		0	(25,689)	(10,885)
Payments of contingent consideration		0	0	(10,989)
Payment of debt issuance costs		(5,488)	(545)	0
Proceeds from exercise of stock options		63	545	2,663
Other financing activities, net		(245)	(1,061)	(1,156)
Net cash provided by (used in) financing activities		8,977	(13,736)	(525)
Effect of exchange rate changes on cash and cash equivalents		(1,407)	(1,973)	948
Increase (decrease) in cash and cash equivalents		15,941	(3,792)	(362)
Cash and cash equivalents, beginning of period	$ 26,770	26,770	30,562	30,924
Cash and cash equivalents, end of period		42,711	26,770	30,562
Supplemental disclosure of cash flow information:
Interest paid		14,355	7,149	4,072
Income taxes paid		3,040	5,810	9,838
Supplemental non-cash investing and financing activities:
Buildings - Build to Suit Leases		0	48,428	0
Repurchases of common stock		0	0	91
Shares issued as payment of contingent consideration		0	0	4,678
Revolving Credit Facility | Credit Agreement
Cash flows from financing activities:
Repayments of lines of credit		(142,583)		(867)
Proceeds from lines of credit			14,539
Revolving Credit Facility | ABL Credit Agreement
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Change in fair value of embedded derivative		102
Cash flows from financing activities:
Proceeds from lines of credit		60,563	0	0
Term Loan Facility | Term Loan Credit Agreement
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Change in fair value of embedded derivative		74
Cash flows from financing activities:
Repayments of lines of credit		(2,500)	0	0
Proceeds from lines of credit		$ 100,000	$ 0	$ 0