Repurchase Agreements (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase, Fair Value of Collateral	$ 685,600
Securities sold under customer repurchase agreements	680,705	$ 641,487
Available-for-sale Securities
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase, Fair Value of Collateral		689,300
Overnight and continuous
Assets Sold under Agreements to Repurchase [Line Items]
Securities sold under customer repurchase agreements	680,700	641,500
Overnight and continuous | US Government Agencies Debt Securities
Assets Sold under Agreements to Repurchase [Line Items]
Securities sold under customer repurchase agreements	485,800	432,800
Overnight and continuous | Commercial Mortgage Backed Securities
Assets Sold under Agreements to Repurchase [Line Items]
Securities sold under customer repurchase agreements	$ 194,900	$ 208,700