Income Taxes - U.S. Tax Reform (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
U.S Tax Reform [Abstract]
Repatriation tax payable		$ 1.1
Repatriation tax payable, current		0.1
Repatriation tax payable, non-current		$ 1.0
Federal statutory rate	21.00%	35.00%	35.00%
Provisional tax credit for reduction in tax rate		$ (3.3)