Equity - Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
AOCI Attributable to Parent, Net of Tax [Roll Forward]
AOCI, beginning balance	$ (299.0)
Other comprehensive income (loss) before reclassifications	134.1	$ (145.6)	$ 230.8
Amounts reclassified from accumulated other comprehensive income (loss)	58.2	(18.2)	(125.6)
Total other comprehensive income (loss), net of tax	192.3	(163.8)	105.2
AOCI, ending balance	(106.7)	(299.0)
Accumulated other comprehensive loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
AOCI, beginning balance	(299.0)	(135.2)	(240.4)
AOCI, ending balance	(106.7)	(299.0)	(135.2)
Unrealized Gains (Losses) on Securities Available for Sale, Net of Tax
AOCI Attributable to Parent, Net of Tax [Roll Forward]
AOCI, beginning balance	1.4	4.2	(4.0)
Other comprehensive income (loss) before reclassifications	(6.6)	(9.3)	11.8
Amounts reclassified from accumulated other comprehensive income (loss)	3.0	6.5	(3.6)
Total other comprehensive income (loss), net of tax	(3.6)	(2.8)	8.2
AOCI, ending balance	(2.2)	1.4	4.2
Unrealized Gains (Losses) on Cash Flow Hedges, Net of Tax
AOCI Attributable to Parent, Net of Tax [Roll Forward]
AOCI, beginning balance	(179.0)	7.8	34.7
Other comprehensive income (loss) before reclassifications	178.2	(165.0)	88.1
Amounts reclassified from accumulated other comprehensive income (loss)	54.6	(21.8)	(115.0)
Total other comprehensive income (loss), net of tax	232.8	(186.8)	(26.9)
AOCI, ending balance	53.8	(179.0)	7.8
Gains (Losses) on Net Investment Hedge, Net of Tax
AOCI Attributable to Parent, Net of Tax [Roll Forward]
AOCI, beginning balance	(8.5)	25.1	3.5
Other comprehensive income (loss) before reclassifications	33.4	(30.7)	28.6
Amounts reclassified from accumulated other comprehensive income (loss)	0.6	(2.9)	(7.0)
Total other comprehensive income (loss), net of tax	34.0	(33.6)	21.6
AOCI, ending balance	25.5	(8.5)	25.1
Unfunded Status of Postretirement Benefit Plans, Net of Tax
AOCI Attributable to Parent, Net of Tax [Roll Forward]
AOCI, beginning balance	(66.3)	(32.8)	(31.3)
Other comprehensive income (loss) before reclassifications	21.5	(33.5)	(1.5)
Amounts reclassified from accumulated other comprehensive income (loss)	0.0	0.0	0.0
Total other comprehensive income (loss), net of tax	21.5	(33.5)	(1.5)
AOCI, ending balance	(44.8)	(66.3)	(32.8)
Currency Translation Adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
AOCI, beginning balance	(46.6)	(139.5)	(243.3)
Other comprehensive income (loss) before reclassifications	(92.4)	92.9	103.8
Amounts reclassified from accumulated other comprehensive income (loss)	0.0	0.0	0.0
Total other comprehensive income (loss), net of tax	(92.4)	92.9	103.8
AOCI, ending balance	$ (139.0)	$ (46.6)	$ (139.5)