Derivative Financial Instruments Notional Amounts and Fair Values of Derivative Financial Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Derivative [Line Items]
Derivative asset, fair value	$ (80,075)	$ (61,688)
Derivative liability, fair value	(49,210)	(47,237)
Derivative asset (liability), net	31,673	14,378
Interest Rate Lock Commitments [Member]
Derivative [Line Items]
Derivative asset, notional amount	140,030	101,700
Derivative liability, notional amount	2,491	1,646
Derivative asset, fair value	(1,759)	(1,148)
Derivative liability, fair value	(17)	(12)
Derivative asset (liability), net	1,742	1,136
Forward Commitments [Member]
Derivative [Line Items]
Derivative asset, notional amount	20,627	1,540
Derivative liability, notional amount	100,002	83,562
Derivative asset, fair value	(55)	(3)
Derivative liability, fair value	(1,062)	(1,066)
Derivative asset (liability), net	(1,007)	(1,063)
Interest Rate Swap with Customer [Member]
Derivative [Line Items]
Derivative asset, notional amount	2,039,265	1,185,144
Derivative liability, notional amount	661,338	1,386,046
Derivative asset, fair value	(66,479)	(33,258)
Derivative liability, fair value	(13,473)	(30,769)
Derivative asset (liability), net	53,006	2,489
Interest Rate Swap With Counterparty [Member]
Derivative [Line Items]
Derivative asset, notional amount	661,338	1,386,046
Derivative liability, notional amount	2,039,265	1,185,144
Derivative asset, fair value	(13,406)	(28,143)
Derivative liability, fair value	(35,533)	(16,338)
Derivative asset (liability), net	(22,127)	11,805
Centrally Cleared Interest Rate Swap with Counterparty [Member]
Derivative [Line Items]
Variation margin	30,600
Variation margin		14,300
Foreign Exchange Contracts With Customer [Member]
Derivative [Line Items]
Derivative asset, notional amount	8,991	5,881
Derivative liability, notional amount	3,414	9,690
Derivative asset, fair value	(225)	(105)
Derivative liability, fair value	(152)	(251)
Derivative asset (liability), net	73	(146)
Foreign Exchange Contracts With Correspondent Banks [Member]
Derivative [Line Items]
Derivative asset, notional amount	4,511	9,220
Derivative liability, notional amount	9,524	6,831
Derivative asset, fair value	(190)	(287)
Derivative liability, fair value	(204)	(130)
Derivative asset (liability), net	$ (14)	$ 157

Derivative Asset, Variation Margin, Obligation to Return Cash, Offset

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Derivative Liability, Variation Margin, Right to Reclaim Cash, Offset

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Nominal or face amount used to calculate payments on the derivative asset.

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Fair values as of the balance sheet date of the net amount of all assets and liabilities resulting from contracts that meet the criteria of being accounted for as derivative instruments.

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Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

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Nominal or face amount used to calculate payments on the derivative liability.

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