Acquisitions, Divestitures and Goodwill (Narrative) (Details) - USD ($)	1 Months Ended	3 Months Ended		12 Months Ended
	May 31, 2018	Mar. 31, 2019	Jul. 01, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2013
Business Acquisition [Line Items]
Goodwill, Acquired During Period				$ 19,000,000	$ (3,000,000)	$ 77,000,000
Finite-lived Intangible Assets Acquired						12,000,000
Proceeds from sale of business, net of transaction costs	$ 11,000,000			0	11,000,000	0
Gain (Loss) on Disposition of Business			$ 8,000,000
Gain (Loss) on Disposition of Business, Net of Tax			$ 5,000,000
Payments for acquired companies, net of cash received				8,000,000	$ 0	$ 93,000,000
Vista Equity Partners contribution percentage						19.70%
Tax deductible goodwill related to acquisitions				$ 28,000,000
RGNext [Member]
Business Acquisition [Line Items]
Noncontrolling Interest, Ownership Percentage by Parent				60.00%			50.00%
Noncontrolling Interest, Ownership Percentage Acquired by Parent				10.00%
Business Combination, Step Acquisition, Equity Interest in Acquiree, Remeasurement Gain		$ 21,000,000
Redeemable Noncontrolling Interest, Equity, Fair Value				$ 32,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net				90,000,000
Goodwill, Acquired During Period				19,000,000
Finite-lived Intangible Assets Acquired				$ 34,000,000
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life				7 years