Organization and Basis of Presentation - Accounting Standards Adopted (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Jan. 01, 2019
Accounting Standards Adopted in 2019
Recognized lease liability on consolidated balance sheet	$ 48.3
Right-of-use asset on consolidated balance sheet	$ 47.4
Practical expedient, ASU No. 2016-02	true
ASU 2016-02
Accounting Standards Adopted in 2019
Recognized lease liability on consolidated balance sheet		$ 50.3
Right-of-use asset on consolidated balance sheet		$ 50.6
ASU 2018-15
Accounting Standards Adopted in 2019
Change in Accounting Principle, Accounting Standards Update, Early Adoption [true false]		true
Hosting arrangements that are service contracts	$ 3.5