Long-Lived Assets (Details Textual) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Finite Lived Intangible Assets [Line Items]
Total amortization expense	$ 5.6	$ 4.0
Estimated total amortization expense 2019	22.3
Estimated total amortization expense 2020	18.8
Estimated total amortization expense 2021	13.9
Estimated total amortization expense 2022	11.6
Estimated total amortization expense 2023	8.2
Client contract costs
Finite Lived Intangible Assets [Line Items]
Total amortization expense	$ 6.0	$ 5.5