Disclosures about Fair Value of Assets and Liabilities - Realized Gains and Losses included in Net Income for Periods in Consolidated Statements of Income (Details) - Non-interest Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Included in net income	$ 1,043	$ 257
Hedged loans
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Included in net income	(26,330)	(4,051)
Interest rate swap agreements liability
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Included in net income	26,330	4,051
Derivative loan commitments
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Included in net income	$ 1,043	$ 257