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Income Taxes (Narrative) (Details) - USD ($) $ in Thousands | 3 Months Ended | 12 Months Ended
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Dec. 31, 2017 | Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Income Tax Disclosure [Abstract] |  |  |  |
Income tax benefits due to ASU 2016-09 |  | $ 4,775 |  |
Net tax benefit recognized from stock compensation plans |  |  | $ 1,055 | $ 3,291
Income tax expense recorded after impact of Tax Act | $ 41,700 |  |  |
Remeasurements of certain deferred tax assets and liabilities, net | 33,100 |  |  |
Tax credits and other tax benefits related to qualified affordable housing partnerships | $ 7,900 |  |  |
Other comprehensive income, available for sale securities, income tax benefit |  | $ (1,500) | $ (16,400) | $ (7,500)

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- Definition Amount of income tax expense (benefit) for remeasurements of certain deferred tax assets and liabilities, and tax credits and other tax benefits related to qualified affordable housing partnerships, due to change in tax rate pursuant to Tax Cuts and Jobs Act. + References No definition available. + Details
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- Definition Tax Cuts And Jobs Act Of 2017, Change In Tax Rate, Affordable Housing Tax Credits And Other Tax Benefits, Income Tax Expense + References No definition available. + Details
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- Definition Amount of reasonable estimate for income tax expense (benefit) for remeasurement of deferred tax from change in tax rate pursuant to Tax Cuts and Jobs Act of 2017. + References No definition available. + Details
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- Definition Amount of increase (decrease) in additional paid in capital (APIC) resulting from a tax benefit (deficiency) associated with an share-based compensation plan other than an employee stock ownership plan (ESOP). + References No definition available. + Details
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- Definition The total recognized tax benefit related to compensation cost for equity-based payment arrangements recognized in income during the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (h)(1)(i) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
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- Definition Amount of tax expense (benefit), after reclassification adjustments, of appreciation (loss) in value of unsold available-for-sale securities, attributable to parent entity. Excludes amounts related to other than temporary impairment (OTTI) loss. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 1A -Subparagraph (c)(3) -URI http://asc.fasb.org/extlink&oid=84161450&loc=SL4573702-111684 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 45 -Paragraph 19 -URI http://asc.fasb.org/extlink&oid=96868048&loc=SL4569616-111683 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 45 -Paragraph 20 -URI http://asc.fasb.org/extlink&oid=96868048&loc=SL4569643-111683 + Details
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