Stockholders' Equity (Reclassifications Out Of Accumulated Other Comprehensive Income) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Gross Amount	$ 18,900,000	$ 5,300,000
Reclassification from AOCI, Current Period, Tax	4,300,000	1,000,000
Net Amount	23,200,000	6,300,000
Foreign currency translation adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net Amount	26,200,000	4,700,000	$ 80,500,000
Foreign currency translation adjustments | Other Non-interest Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Gross Amount	24,100,000	3,500,000
Reclassification from AOCI, Current Period, Tax	2,100,000	1,200,000
Net Amount	26,200,000	4,700,000
Changes in benefit plan net gain (loss) and prior service (cost) credit
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net Amount	700,000	1,600,000	$ 2,000,000
Changes in benefit plan net gain (loss) and prior service (cost) credit | Operating Expenses
Accumulated Other Comprehensive Income (Loss) [Line Items]
Gross Amount	700,000	1,800,000
Reclassification from AOCI, Current Period, Tax	0	(200,000)
Net Amount	700,000	1,600,000
Unrealized net gains (losses) on available for sale securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net Amount	(3,700,000)	0
Unrealized net gains (losses) on available for sale securities | Other Non-interest Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Gross Amount	(5,900,000)	0
Reclassification from AOCI, Current Period, Tax	2,200,000	0
Net Amount	$ (3,700,000)	$ 0