Shareholders' Equity (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Jan. 01, 2016
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total stockholders’ equity, beginning balance			$ 1,246.6	$ 1,133.2
Cumulative effect of an accounting change					$ 43.9
Total stockholders’ equity, beginning balance	$ 1,391.5	$ 1,288.4	1,246.6	1,133.2	1,177.1
Net income	(18.9)	52.3	47.0	85.1
Other comprehensive income, net of tax	31.4	(13.6)	72.9	0.2
Recognition of stock-based compensation			21.3	21.6
Exercise of stock options			12.9	5.9
Treasury share repurchase			(8.3)
Dividends paid to noncontrolling interests			(0.9)	(1.5)
Total stockholders’ equity, ending balance	1,391.5	1,288.4	1,391.5	1,288.4
Parent [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total stockholders’ equity, beginning balance			1,125.1	1,065.7
Cumulative effect of an accounting change					43.9
Total stockholders’ equity, beginning balance	1,266.2	1,220.1	1,125.1	1,065.7	1,109.6
Net income			43.3	82.6
Other comprehensive income, net of tax			71.9	0.4
Recognition of stock-based compensation			21.3	21.6
Exercise of stock options			12.9	5.9
Treasury share repurchase			(8.3)
Dividends paid to noncontrolling interests			0.0	0.0
Total stockholders’ equity, ending balance	1,266.2	1,220.1	1,266.2	1,220.1
Noncontrolling Interest [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total stockholders’ equity, beginning balance			121.5	67.5
Total stockholders’ equity, beginning balance	125.3	68.3	121.5	67.5	$ 67.5
Net income			3.7	2.5
Other comprehensive income, net of tax			1.0	(0.2)
Recognition of stock-based compensation			0.0	0.0
Exercise of stock options			0.0	0.0
Treasury share repurchase			0.0
Dividends paid to noncontrolling interests			(0.9)	(1.5)
Total stockholders’ equity, ending balance	$ 125.3	$ 68.3	$ 125.3	$ 68.3