Summary of Significant Accounting Policies, Foreign Currency Translation (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Foreign Currency Translation [Abstract]
Cumulative translation adjustment related to foreign currency adjustment	$ (79.9)	$ (66.4)	$ (84.7)
Cumulative translation adjustment related to foreign currency adjustment, tax	$ 7.9	$ 5.8	$ 13.4

Accumulated adjustment, net of tax, that results from the process of translating subsidiary financial statements and foreign equity investments into the reporting currency from the functional currency of the reporting entity, net of reclassification of realized foreign currency translation gains or losses.

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