CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities attributable to continuing operations:
Net (loss) income and comprehensive (loss) income	$ (48,255,000)	$ 17,828,000	$ 96,499,000
Less: Loss from discontinued operations, net of tax	25,689,000	21,632,000	12,820,000
(Loss) income from continuing operations	(22,566,000)	39,460,000	109,319,000
Adjustments to reconcile income from continuing operations to net cash provided by operating activities attributable to continuing operations:
Loss (gain) on impairments and disposal of assets	1,160,000	(695,000)	2,210,000
Amortization of intangibles	53,078,000	55,241,000	23,468,000
Depreciation	14,201,000	10,998,000	7,385,000
Rental amortization of intangibles and depreciation	0	0	630,000
Non-cash compensation expense	53,733,000	52,167,000	44,365,000
Deferred income taxes	(9,628,000)	(8,555,000)	(63,901,000)
Change in fair value of contingent consideration	5,327,000	28,402,000	10,788,000
Bad debt expense	1,785,000	1,697,000	880,000
Amortization of debt issuance costs	3,474,000	1,974,000	1,776,000
Write-off of previously-capitalized debt issuance costs	0	333,000	0
Amortization of convertible debt discount	19,570,000	12,016,000	11,397,000
Loss on extinguishment of debt	7,768,000	0	0
Reduction in carrying amount of ROU asset, offset by change in operating lease liabilities	8,888,000	213,000	0
Changes in current assets and liabilities:
Accounts receivable	21,861,000	(22,457,000)	(16,820,000)
Prepaid and other current assets	(952,000)	(3,258,000)	(2,985,000)
Accounts payable, accrued expenses and other current liabilities	(8,013,000)	(2,322,000)	14,270,000
Current contingent consideration	(25,787,000)	(12,500,000)	(21,912,000)
Income taxes receivable	(10,598,000)	4,548,000	3,669,000
Other, net	(2,002,000)	(88,000)	(591,000)
Net cash provided by operating activities attributable to continuing operations	111,299,000	157,174,000	123,948,000
Cash flows from investing activities attributable to continuing operations:
Capital expenditures	(42,149,000)	(20,041,000)	(14,907,000)
Proceeds from the sale of fixed assets	0	24,077,000	0
Equity investment	(80,000,000)	0	0
Net cash used in investing activities attributable to continuing operations	(122,149,000)	(101,060,000)	(383,038,000)
Cash flows from financing activities attributable to continuing operations:
Payments related to net-share settlement of stock-based compensation, net of proceeds from exercise of stock options	(3,910,000)	(8,406,000)	2,217,000
Proceeds from the issuance of 0.625% Convertible Senior Notes	575,000,000	0	0
Repurchase of 0.625% Convertible Senior Notes	(233,862,000)	0	0
Payment of convertible note hedge on the 0.50% Convertible Senior Notes	(124,200,000)	0	0
Termination of convertible note hedge on the 0.625% Convertible Senior Notes	109,881,000	0	0
Proceeds from the sale of warrants related to the 0.50% Convertible Senior Notes	61,180,000	0	0
Termination of warrants related to the 0.625% Convertible Senior Notes	(94,292,000)	0	0
Net (repayment of) proceeds from revolving credit facility	(75,000,000)	(50,000,000)	125,000,000
Payment of debt issuance costs	(16,568,000)	(2,518,000)	(583,000)
Contingent consideration payments	(4,755,000)	(21,275,000)	(27,588,000)
Purchase of treasury stock	0	(5,470,000)	(93,704,000)
Acquisition of noncontrolling interest	0	0	(499,000)
Other financing activities	(184,000)	(9,000)	0
Net cash provided by (used in) financing activities attributable to continuing operations	193,290,000	(87,678,000)	4,843,000
Total cash provided by (used in) continuing operations	182,440,000	(31,564,000)	(254,247,000)
Discontinued operations:
Net cash used in operating activities attributable to discontinued operations	(72,730,000)	(13,255,000)	(13,236,000)
Total cash used in discontinued operations	(72,730,000)	(13,255,000)	(13,236,000)
Net increase (decrease) in cash, cash equivalents, restricted cash, and restricted cash equivalents	109,710,000	(44,819,000)	(267,483,000)
Cash, cash equivalents, restricted cash, and restricted cash equivalents at beginning of period	60,339,000	105,158,000	372,641,000
Cash, cash equivalents, restricted cash, and restricted cash equivalents at end of period	170,049,000	60,339,000	105,158,000
Supplemental Cash Flow Elements [Abstract]
Increase (decrease) in capital expenditures included in accounts payable and accrued expenses	4,196,000	(946,000)	949,000
Capital additions from tenant improvement allowance	0	1,111,000	0
Supplemental cash flow information:
Interest paid	4,741,000	7,005,000	3,593,000
Income tax payments	561,000	25,000	541,000
Income tax refunds	60,000	4,743,000	5,678,000
ValuePenguin
Cash flows from investing activities attributable to continuing operations:
Payments to acquire business, net of cash acquired	0	(105,578,000)	0
QuoteWizard
Adjustments to reconcile income from continuing operations to net cash provided by operating activities attributable to continuing operations:
Change in fair value of contingent consideration	3,980,000	27,103,000	6,833,000
Cash flows from investing activities attributable to continuing operations:
Payments to acquire business, net of cash acquired	0	482,000	(297,072,000)
Student Loan Hero
Cash flows from investing activities attributable to continuing operations:
Payments to acquire business, net of cash acquired	0	0	(59,483,000)
Ovation
Adjustments to reconcile income from continuing operations to net cash provided by operating activities attributable to continuing operations:
Change in fair value of contingent consideration	1,270,000	26,000	1,654,000
Cash flows from investing activities attributable to continuing operations:
Payments to acquire business, net of cash acquired	0	0	(11,566,000)
SnapCap
Adjustments to reconcile income from continuing operations to net cash provided by operating activities attributable to continuing operations:
Change in fair value of contingent consideration	77,000	2,220,000	(330,000)
Changes in current assets and liabilities:
Current contingent consideration	(6,000,000.0)
Cash flows from investing activities attributable to continuing operations:
Payments to acquire businesses	0	0	(10,000)
Cash flows from financing activities attributable to continuing operations:
Contingent consideration payments	(3,300,000)	(3,000,000.0)
DepositAccounts
Adjustments to reconcile income from continuing operations to net cash provided by operating activities attributable to continuing operations:
Change in fair value of contingent consideration	0	$ (947,000)	1,979,000
Changes in current assets and liabilities:
Current contingent consideration	$ 0
Cash flows from financing activities attributable to continuing operations:
Contingent consideration payments			$ (4,000,000.0)