CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenues
Total revenues		$ 1,370,598	$ 1,294,322	$ 1,258,294
Operating expenses
Cost of revenue	[1]	638,871	622,459	617,453
Research and development		144,310	139,293	146,573
Selling and marketing		126,539	103,567	123,684
General and administrative		123,801	152,468	135,296
Depreciation and amortization		127,180	131,791	111,532
Total operating expenses		1,160,701	1,149,578	1,134,538
Operating income		209,897	144,744	123,756
Other income (expense)
Interest expense		(45,060)	(56,630)	(64,033)
Interest income		11,522	11,628	11,967
Other, net		(1,294)	(1,116)	520
Total other income (expense)		(34,832)	(46,118)	(51,546)
Income before income taxes		175,065	98,626	72,210
Income tax expense		47,274	25,966	5,148
Net income		$ 127,791	$ 72,660	$ 67,062
Income per common share
Basic (in dollars per share)		$ 1.09	$ 0.62	$ 0.58
Diluted (in dollars per share)		$ 1.08	$ 0.62	$ 0.57
Weighted average common shares outstanding
Basic (in shares)		117,407	116,397	116,175
Diluted (in shares)		118,647	118,079	118,571
Software as a service and platform as a service
Revenues
Total revenues		$ 774,342	$ 769,180	$ 677,669
License
Revenues
Total revenues		319,867	246,896	288,261
Maintenance
Revenues
Total revenues		210,499	211,697	213,409
Services
Revenues
Total revenues		$ 65,890	$ 66,549	$ 78,955

[1] The cost of revenue excludes charges for depreciation but includes amortization of purchased and developed software for resale.