Business Combination - Schedule of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Jul. 03, 2017	Dec. 31, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Goodwill	$ 398,575		$ 370,986	$ 368,133
PayGroup
Business Acquisition [Line Items]
Cash and cash equivalents		$ 1,834
Accounts Receivable		3,778
Prepaid expenses and other assets		535
Property and equipment		1,082
Long-term deferred tax asset		834
Goodwill		26,931
Other intangible assets		19,340
Other long-term assets		499
Total assets acquired		54,833
Accrued liabilities		2,092
Accounts payable		1,965
Unearned income		946
Long-term debt		1,141
Long-term deferred tax liability		2,904
Other long-term liabilities		1,115
Total liabilities assumed		$ 10,163