Loans and Allowance for Credit Losses Allowance for Credit Losses (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018
Receivables [Abstract]
ACL - loans	$ 266,825		$ 163,622	$ 166,135	$ 170,233	$ 160,537
ACL - OBS credit exposure	15,533		2,587
Total ACL	$ 282,358	$ 272,920	$ 166,209	$ 172,797	$ 176,941	$ 169,410

Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

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Name:	us-gaap_FinancingReceivableAllowanceForCreditLosses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant