Equity Accumulated Other Comprehensive Income (Loss) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Jan. 01, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), net of tax beginning balance	$ (240,400,000)	$ (318,400,000)
Balance, January 1, 2018	(240,400,000)	(318,400,000)	$ (316,900,000)
Other comprehensive income (loss), before reclassifications, net of tax	37,300,000	(24,400,000)
Amounts reclassified from accumulated other comprehensive income, net of tax	(16,700,000)	37,400,000
Other comprehensive income (loss), net of tax	20,600,000	13,200,000
Accumulated other comprehensive income (loss), net of tax ending balance	(219,800,000)	(303,900,000)
Other comprehensive income (loss), net of tax	20,600,000	13,000,000
Unrealized gains (losses) on securities available for sale
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), net of tax beginning balance	(4,000,000)	(1,600,000)
Balance, January 1, 2018	(4,000,000)	(1,600,000)	(100,000)
Other comprehensive income (loss), before reclassifications, net of tax	7,100,000	(8,200,000)
Amounts reclassified from accumulated other comprehensive income, net of tax	(200,000)	6,000,000
Other comprehensive income (loss), net of tax	6,900,000	(2,200,000)
Accumulated other comprehensive income (loss), net of tax ending balance	2,900,000	(2,300,000)
Unrealized gains (losses) on cash flow hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), net of tax beginning balance	34,700,000	(104,500,000)
Balance, January 1, 2018	34,700,000	(104,500,000)	(104,500,000)
Other comprehensive income (loss), before reclassifications, net of tax	31,200,000	(60,400,000)
Amounts reclassified from accumulated other comprehensive income, net of tax	(14,300,000)	31,400,000
Other comprehensive income (loss), net of tax	16,900,000	(29,000,000)
Accumulated other comprehensive income (loss), net of tax ending balance	51,600,000	(133,500,000)
Gains (losses) on net investment hedge
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), net of tax beginning balance	3,500,000	0
Balance, January 1, 2018	3,500,000	0	0
Other comprehensive income (loss), before reclassifications, net of tax	16,200,000	0
Amounts reclassified from accumulated other comprehensive income, net of tax	(2,200,000)	0
Other comprehensive income (loss), net of tax	14,000,000	0
Accumulated other comprehensive income (loss), net of tax ending balance	17,500,000	0
Unfunded status of postretirement benefit plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), net of tax beginning balance	(31,300,000)	(36,800,000)
Balance, January 1, 2018	(31,300,000)	(36,800,000)	(36,800,000)
Other comprehensive income (loss), before reclassifications, net of tax	600,000	(500,000)
Amounts reclassified from accumulated other comprehensive income, net of tax	0	0
Other comprehensive income (loss), net of tax	600,000	(500,000)
Accumulated other comprehensive income (loss), net of tax ending balance	(30,700,000)	(37,300,000)
Currency translation adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), net of tax beginning balance	(243,300,000)	(175,500,000)
Balance, January 1, 2018	(243,300,000)	(175,500,000)	(175,500,000)
Other comprehensive income (loss), before reclassifications, net of tax	(17,800,000)	44,700,000
Amounts reclassified from accumulated other comprehensive income, net of tax	0	0
Other comprehensive income (loss), net of tax	(17,800,000)	44,700,000
Accumulated other comprehensive income (loss), net of tax ending balance	$ (261,100,000)	$ (130,800,000)
Accounting Standards Update 2016-01
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cumulative effect of new accounting principle in period of adoption			1,500,000
Accounting Standards Update 2016-01 | Unrealized gains (losses) on securities available for sale
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cumulative effect of new accounting principle in period of adoption			1,500,000
Accounting Standards Update 2016-01 | Unrealized gains (losses) on cash flow hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cumulative effect of new accounting principle in period of adoption			0
Accounting Standards Update 2016-01 | Gains (losses) on net investment hedge
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cumulative effect of new accounting principle in period of adoption			0
Accounting Standards Update 2016-01 | Unfunded status of postretirement benefit plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cumulative effect of new accounting principle in period of adoption			0
Accounting Standards Update 2016-01 | Currency translation adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cumulative effect of new accounting principle in period of adoption			$ 0