Investment Securities - Qualified Affordable Housing Projects (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Investments in Affordable Housing Projects [Abstract]
Investments in qualified affordable housing projects, net	$ 318,575	$ 174,214
Other liabilities	205,685	100,891
Investment Holdings [Line Items]
Tax credits and other tax benefits recognized	24,047	17,296	$ 15,404
Amortization expense included in provision for income taxes	$ 18,876	17,362	$ 12,145
Low Income Housing Tax Credit Funds
Investment Holdings [Line Items]
Cumulative effect adjustment		$ 3,800

Amount of affordable housing tax credits and other tax benefits recognized.

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Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations, attributable to increase (decrease) in the income tax rates.

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Amount of commitment or contingent commitments to qualified affordable housing project investments.

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