CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenues		$ 1,416,722	$ 1,158,829	$ 1,050,464
Cost of revenues	[1]	188,053	178,403	187,332
Gross profit		1,228,669	980,426	863,132
Operating expenses:
Sales and marketing	[1]	493,049	366,359	327,661
Research, development and engineering	[1]	78,874	57,148	44,651
General and administrative	[1]	456,777	418,579	402,597
Goodwill impairment on business		32,629	0	0
Total operating expenses		1,061,329	842,086	774,909
Income from operations		167,340	138,340	88,223
Interest expense, net		(72,023)	(56,188)	(26,886)
Loss on debt extinguishment, net		(5,274)	0	0
(Loss) gain on sale of businesses		(21,798)	17,122	0
Impairment		(16,677)	(20,991)	(4,211)
Unrealized gain on short-term investment		298,490	0	0
Other income (expense), net		1,293	65	(2,305)
Income from continuing operations before income taxes and income from equity method investment, net of income taxes		351,351	78,348	54,821
Income tax (benefit) expense		(14,199)	38,350	13,760
Net investment income (loss)		35,845	(11,338)	(168)
Net income from continuing operations		401,395	28,660	40,893
Income from discontinued operations, net of income taxes		95,319	122,008	177,913
Net income		$ 496,714	$ 150,668	$ 218,806
Net income per common share from continuing operations:
Basic (in dollars per share)		$ 8.74	$ 0.62	$ 0.85
Diluted (in dollars per share)		8.38	0.61	0.83
Net income per common share from discontinued operations:
Basic (in dollars per share)		2.08	2.62	3.69
Diluted (in dollars per share)		1.99	2.58	3.57
Net income per common share:
Basic (in dollars per share)		10.81	3.24	4.52
Diluted (in dollars per share)		$ 10.37	$ 3.18	$ 4.39
Weighted average shares outstanding:
Basic (in shares)		45,893,928	46,308,825	47,647,397
Diluted (in shares)		47,862,745	47,115,609	49,025,684
Cash dividends paid per common share (in dollars per share)		$ 0	$ 0	$ 0.90
Share-based compensation expense		$ 24,129	$ 22,520	$ 22,466
Cost of revenues
Weighted average shares outstanding:
Share-based compensation expense		306	332	154
Sales and marketing
Weighted average shares outstanding:
Share-based compensation expense		1,288	1,011	946
Research, development and engineering
Weighted average shares outstanding:
Share-based compensation expense		1,984	1,396	976
General and administrative
Weighted average shares outstanding:
Share-based compensation expense		$ 20,551	$ 19,781	$ 20,390

[1] (1) Includes share-based compensation expense as follows: Cost of revenues$306 $332 $154 Sales and marketing1,288 1,011 946 Research, development and engineering1,984 1,396 976 General and administrative20,551 19,781 20,390 Total$24,129 $22,520 $22,466