Loans (Narrative) (Details) $ in Thousands		Sep. 30, 2020 USD ($) loan	Dec. 31, 2019 USD ($)
Carrying value of PPP loans		$ 216,800
Loans Receivable Net Deferred Cost Originated		670	$ 5,300
Loans Receivable Net Deferred Premium on Purchased Loans		919	995
Loans pledged as collateral		2,200,000	2,100,000
Past due loans included in nonaccrual loans		8,800	11,500
Nonaccrual loans with no ACL		2,900
Residential loans in process of foreclosure		2,900	5,800
Nonaccrual loans current on payment		$ 5,900
Number of executed loan modifications due to COVID-19 | loan		617
Balance of executed loan modifications due to COVID-19		$ 685,400
Number of loans ineligible for TDR relief under CARES Act | loan		17
Balances of loans ineligible for TDR relief under CARES Act		$ 7,800
Number of active deferrals due to COVID-19 | loan		253
Balance of active deferments due to COVID-19		$ 418,200
Individually analyzed loans		15,700
Collateral dependent loans	[1]	4,282,047	$ 3,892,999
Collateral Dependent Individually Analyzed
Collateral dependent loans		$ 7,510

[1] Includes net unamortized loan origination fees of $670 thousand at September 30, 2020 and net unamortized loan origination costs of $5.3 million, at December 31, 2019 and net unamortized premiums on purchased loans of $919 thousand and $995 thousand, respectively, at September 30, 2020 and December 31, 2019.