Description of Business and Summary of Significant Accounting Policies (Goodwill) (Details) - USD ($)						3 Months Ended	12 Months Ended
	Nov. 01, 2017	Jun. 01, 2017	Apr. 01, 2017	Nov. 02, 2016	Jun. 01, 2015	Jun. 30, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2017	Oct. 01, 2017	Sep. 30, 2017	Sep. 01, 2017	Nov. 01, 2016	Jul. 01, 2016	Dec. 02, 2014
Goodwill [Line Items]
Goodwill, Impairment Loss							$ 0	$ 0	$ 0
Business acquisition, purchase price allocation, goodwill							441,404,000	402,259,000	402,259,000	$ 666,863,000
Goodwill [Roll Forward]
Goodwill, beginning balance							441,404,000	402,259,000
Additions for current year acquisitions							233,095,000	35,787,000
Purchase accounting adjustments for prior year acquisitions							(12,158,000)	4,298,000
Foreign currency translation adjustments							4,522,000	(940,000)
Goodwill, ending balance							$ 666,863,000	441,404,000	$ 402,259,000
Fair Value Inputs, Discount Rate							13.50%
WDEV
Goodwill [Roll Forward]
Business Combination, Escrow Holding Period				38 months			38 months
ItzCash
Goodwill [Roll Forward]
Business Combination, Escrow Holding Period			36 months
beBetter
Goodwill [Roll Forward]
Business Combination, Escrow Holding Period		24 months
Via
Goodwill [Roll Forward]
Business Combination, Escrow Holding Period	12 months
Oakstone, EbixHealth JV, IHAC(Hope), WDEV [Member], Itzcash, beBetter, Youirst, Wallstreet, Paul Merchants, and Via [Member]
Goodwill [Roll Forward]
Additions for current year acquisitions							$ 220,937,000
PB Systems
Goodwill [Roll Forward]
Business Combination, Escrow Holding Period					24 months
Final Allocation | Oakstone, EbixHealth JV, IHAC(Hope), WDEV [Member], Itzcash, beBetter, Youirst, Wallstreet, Paul Merchants, and Via [Member]
Goodwill [Line Items]
Business acquisition, purchase price allocation, goodwill							220,937,000			220,937,000
Goodwill [Roll Forward]
Goodwill, ending balance							220,937,000
Final Allocation | PB Systems
Goodwill [Line Items]
Business acquisition, purchase price allocation, goodwill						$ 11,200,000
Goodwill [Roll Forward]
Goodwill, ending balance						11,200,000
Final Allocation | PB Systems, EbixHealth JV, IHAC(Hope), and WDEV [Member]
Goodwill [Line Items]
Business acquisition, purchase price allocation, goodwill							40,085,000	40,085,000
Goodwill [Roll Forward]
Goodwill, beginning balance							$ 40,085,000
Goodwill, ending balance								$ 40,085,000
Final Allocation Adjustment [Member] | Oakstone
Goodwill [Line Items]
Business acquisition, purchase price allocation, goodwill																$ 948,000
Final Allocation Adjustment [Member] | EbixHealth JV
Goodwill [Line Items]
Business acquisition, purchase price allocation, goodwill															$ (7,500,000)
Final Allocation Adjustment [Member] | Hope Health
Goodwill [Line Items]
Business acquisition, purchase price allocation, goodwill														$ (289,000)
Final Allocation Adjustment [Member] | WDEV
Goodwill [Line Items]
Business acquisition, purchase price allocation, goodwill														(5,317,000)
Final Allocation Adjustment [Member] | PB Systems
Goodwill [Line Items]
Business acquisition, purchase price allocation, goodwill					$ 4,298,000
Goodwill [Roll Forward]
Purchase accounting adjustments for prior year acquisitions						$ 4,300,000
Goodwill, ending balance					4,298,000
Preliminary Allocation [Member] | EbixHealth JV
Goodwill [Line Items]
Business acquisition, purchase price allocation, goodwill															$ 20,839,000
Preliminary Allocation [Member] | Hope Health
Goodwill [Line Items]
Business acquisition, purchase price allocation, goodwill														1,333,000
Preliminary Allocation [Member] | WDEV
Goodwill [Line Items]
Business acquisition, purchase price allocation, goodwill														$ 13,615,000
Preliminary Allocation [Member] | ItzCash
Goodwill [Line Items]
Business acquisition, purchase price allocation, goodwill			$ 119,766,000
Goodwill [Roll Forward]
Goodwill, ending balance			$ 119,766,000
Preliminary Allocation [Member] | beBetter
Goodwill [Line Items]
Business acquisition, purchase price allocation, goodwill		$ 447,000
Goodwill [Roll Forward]
Goodwill, ending balance		$ 447,000
Preliminary Allocation [Member] | YouFirst
Goodwill [Line Items]
Business acquisition, purchase price allocation, goodwill													$ 7,395,000
Preliminary Allocation [Member] | Wall Street
Goodwill [Line Items]
Business acquisition, purchase price allocation, goodwill											$ 6,113,000
Preliminary Allocation [Member] | Paul Merchants
Goodwill [Line Items]
Business acquisition, purchase price allocation, goodwill	$ 38,589,000
Goodwill [Roll Forward]
Goodwill, ending balance	38,589,000
Preliminary Allocation [Member] | Via
Goodwill [Line Items]
Business acquisition, purchase price allocation, goodwill	60,785,000
Goodwill [Roll Forward]
Goodwill, ending balance	$ 60,785,000
Preliminary Allocation [Member] | PB Systems
Goodwill [Line Items]
Business acquisition, purchase price allocation, goodwill					6,800,000
Goodwill [Roll Forward]
Goodwill, ending balance					$ 6,800,000
RCS
Goodwill [Line Items]
Reporting Unit, Assessed Fair Value										158,000,000
Reporting Unit, Amount of Fair Value in Excess of Carrying Amount										$ 42,400,000
Reporting Unit, Percentage of Fair Value in Excess of Carrying Amount										36.70%
Reporting Unit, Excess Carrying Value of Assessed Fair Value										$ 115,600,000
Business acquisition, purchase price allocation, goodwill												$ 78,200,000
Goodwill [Roll Forward]
Fair Value Inputs, Discount Rate							16.00%
Minimum [Member] | RCS
Goodwill [Line Items]
Fair Value Inputs, Long-term Revenue Growth Rate							7.50%
Maximum [Member] | RCS
Goodwill [Line Items]
Fair Value Inputs, Long-term Revenue Growth Rate							12.50%