Balance Sheet Offsetting - Schedule of Assets and Liabilities Subject to an Enforceable Master Netting Arrangement or Repurchase Agreements (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Liabilities:
Repurchase Agreements, Gross Amounts of Recognized Liabilities	$ 600,590	$ 604,306
Repurchase Agreements, Gross Amounts Offset in the Statements of Condition	0	0
Repurchase Agreements, Net Amounts of Liabilities Presented in the Statements of Condition	600,590	604,306
Securities Sold under Agreements to Repurchase, Net Amount Offset Against Collateral	0	0
Repurchase Agreements, Fair Value of Collateral Pledged	600,590	604,306
Private Institutions
Liabilities:
Repurchase Agreements, Gross Amounts of Recognized Liabilities	600,000	600,000
Repurchase Agreements, Gross Amounts Offset in the Statements of Condition	0	0
Repurchase Agreements, Net Amounts of Liabilities Presented in the Statements of Condition	600,000	600,000
Securities Sold under Agreements to Repurchase, Net Amount Offset Against Collateral	0	0
Repurchase Agreements, Fair Value of Collateral Pledged	600,000	600,000
Government Entities
Liabilities:
Repurchase Agreements, Gross Amounts of Recognized Liabilities	590	4,306
Repurchase Agreements, Gross Amounts Offset in the Statements of Condition	0	0
Repurchase Agreements, Net Amounts of Liabilities Presented in the Statements of Condition	590	4,306
Securities Sold under Agreements to Repurchase, Net Amount Offset Against Collateral	0	0
Repurchase Agreements, Fair Value of Collateral Pledged	590	4,306
Interest Rate Swap Agreements | Institutional Counterparties
Assets:
Gross Amounts of Recognized Assets	5	584
Gross Amounts Offset in the Statements of Condition	0	0
Net Amounts of Assets Presented in the Statements of Condition	5	584
Netting Adjustments per Master Netting Arrangements	5	584
Gross Amounts Not Offset in the Statements of Condition - FV of collateral pledged	0	0
Derivative Assets, Net Amount	0	0
Liabilities:
Gross Amounts of Recognized Liabilities	17,202	5,361
Gross Amounts Offset in the Statements of Condition	0	0
Net Amounts of Liabilities Presented in the Statements of Condition	17,202	5,361
Derivative Liability, Netting Adjustments per Master Netting Arrangements	5	584
Derivative, Collateral, Right to Reclaim Securities	7,911	3,818
Derivative Liabilities, Net Amount	$ 9,286	$ 959