Accumulated Other Comprehensive Income (Loss) Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Accumulated other comprehensive income [Line Items]
Balance, as of the beginning of the period			$ (319.9)	$ (224.0)
Other comprehensive income loss before reclassifications			(15.4)	(54.8)
Amounts reclassified from accumulated other comprehensive income loss			(3.5)	(4.0)
Net current period other comprehensive income loss	$ (13.6)	$ (23.5)	(18.9)	(58.8)
Balance, as of the end of the period	(338.8)	(282.8)	(338.8)	(282.8)
Accumulated Net Unrealized Investment Gain (Loss)
Accumulated other comprehensive income [Line Items]
Balance, as of the beginning of the period			(10.8)	(0.8)
Other comprehensive income loss before reclassifications			5.1	6.6
Amounts reclassified from accumulated other comprehensive income loss			0.5	0.4
Net current period other comprehensive income loss			5.6	7.0
Balance, as of the end of the period	(5.2)	6.2	(5.2)	6.2
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges
Accumulated other comprehensive income [Line Items]
Balance, as of the beginning of the period			57.8	10.2
Other comprehensive income loss before reclassifications			(122.8)	(13.9)
Amounts reclassified from accumulated other comprehensive income loss			(4.0)	(4.4)
Net current period other comprehensive income loss			(126.8)	(18.3)
Balance, as of the end of the period	(69.0)	(8.1)	(69.0)	(8.1)
Accumulated Defined Benefit Plans Adjustment
Accumulated other comprehensive income [Line Items]
Balance, as of the beginning of the period			(32.7)	(37.8)
Other comprehensive income loss before reclassifications			(0.5)	0.9
Amounts reclassified from accumulated other comprehensive income loss			0.0	0.0
Net current period other comprehensive income loss			(0.5)	0.9
Balance, as of the end of the period	(33.2)	(36.9)	(33.2)	(36.9)
Accumulated Translation Adjustment
Accumulated other comprehensive income [Line Items]
Balance, as of the beginning of the period			(334.2)	(195.6)
Other comprehensive income loss before reclassifications			102.8	(48.4)
Amounts reclassified from accumulated other comprehensive income loss			0.0	0.0
Net current period other comprehensive income loss			102.8	(48.4)
Balance, as of the end of the period	$ (231.4)	$ (244.0)	$ (231.4)	$ (244.0)