Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Statement of Cash Flows [Abstract]
Net loss	$ (15,701)	$ (21,911)
Loss from discontinued operations, net of taxes	(168)	(147)
Net loss from continuing operations	(15,533)	(21,764)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	8,903	10,204
Goodwill impairment	0	8,264
Deferred income taxes	50	(397)
Bad debt expense and other reserves	468	3,485
Stock-based compensation	11,542	12,025
Increase in the fair value of contingent consideration liability	41	121
Amortization of lease right-of-use assets	2,142	3,002
Loss from equity method investment	686	889
Impairment of right-of-use assets and write-off and loss on disposal of finite-lived assets	1,666	41
Other noncash expense	219	0
Changes in operating assets and liabilities:
Accounts receivable	9,620	(1,428)
Prepaid expenses and other assets	(1,416)	(685)
Accounts payable	3,250	(11,300)
Accrued employee expenses	(1,171)	4,410
Operating lease liabilities	(2,551)	(3,705)
Accrued expenses and other liabilities	(2,394)	(8,468)
Other liabilities	(366)	905
Net cash provided by operating activities - continuing operations	15,156	(4,401)
Net cash provided by operating activities - discontinued operations	(168)	6,090
Net cash provided by operating activities	14,988	1,689
Cash flows from investing activities
Purchase of property and equipment	(5,410)	(5,568)
Net cash used in investing activities - continuing operations	(5,410)	(5,568)
Net cash provided by (used in) investing activities - discontinued operations	7,500	(726)
Net cash provided by (used in) investing activities	2,090	(6,294)
Cash flows from financing activities
Payment of contingent consideration liability	(2,214)	(2,263)
Proceeds from exercise of common stock options	1,344	3
Taxes paid related to net share settlement of equity awards	(3,049)	(1,583)
Payments for the repurchase of common stock	(19,400)	0
Net cash used in financing activities	(23,319)	(3,843)
Net increase in cash and cash equivalents	(6,241)	(8,448)
Cash and cash equivalents at beginning of period	273,314	181,534
Cash and cash equivalents at end of period	267,073	173,086
Supplemental disclosures of non-cash activities
Stock-based compensation capitalized for software development	697	700
Capitalized assets included in accounts payable, accrued employee expenses and other accrued expenses	850	410
Capitalized asset retirement costs included in property and equipment	$ 0	$ 498