Derivative Financial Instruments, Effect on Statement of Operations (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Effect of derivative financial instruments on the condensed consolidated financial statements of operations [Abstract]
Loss Recognized in Other Comprehensive Loss (Effective Portion)	$ 0	$ (406)
Fair Value Hedge Designation [Member]
Effect of derivative financial instruments on the condensed consolidated financial statements of operations [Abstract]
Gain (Loss) Recognized in Income	5,225	(546)
Fair Value Hedge Designation [Member] | Interest Rate Swap [Member] | Interest and Fees on Loans [Member]
Effect of derivative financial instruments on the condensed consolidated financial statements of operations [Abstract]
Gain (Loss) Recognized in Income	352	(546)
Fair Value Hedge Designation [Member] | Interest Rate Swap [Member] | Interest on Securities Available for Sale - Tax-exempt [Member]
Effect of derivative financial instruments on the condensed consolidated financial statements of operations [Abstract]
Gain (Loss) Recognized in Income	4,873	0
Cash Flow Hedge Designation [Member]
Effect of derivative financial instruments on the condensed consolidated financial statements of operations [Abstract]
Loss Recognized in Other Comprehensive Loss (Effective Portion)	0	(406)
Loss Reclassified from Accumulated Other Comprehensive Income into Income (Effective Portion)	0	(75)
Cash Flow Hedge Designation [Member] | Interest-Rate Cap Agreements [Member]
Effect of derivative financial instruments on the condensed consolidated financial statements of operations [Abstract]
Loss Recognized in Other Comprehensive Loss (Effective Portion)	0	(14)
Cash Flow Hedge Designation [Member] | Interest-Rate Cap Agreements [Member] | Interest Expense [Member]
Effect of derivative financial instruments on the condensed consolidated financial statements of operations [Abstract]
Loss Reclassified from Accumulated Other Comprehensive Income into Income (Effective Portion)	0	(53)
Cash Flow Hedge Designation [Member] | Fixed Income Interest Rate [Member] | Interest Rate Swap [Member]
Effect of derivative financial instruments on the condensed consolidated financial statements of operations [Abstract]
Loss Recognized in Other Comprehensive Loss (Effective Portion)	0	(392)
Cash Flow Hedge Designation [Member] | Fixed Income Interest Rate [Member] | Interest Rate Swap [Member] | Interest Expense [Member]
Effect of derivative financial instruments on the condensed consolidated financial statements of operations [Abstract]
Loss Reclassified from Accumulated Other Comprehensive Income into Income (Effective Portion)	0	(22)
No Hedge Designation [Member]
Effect of derivative financial instruments on the condensed consolidated financial statements of operations [Abstract]
Gain (Loss) Recognized in Income	(1,852)	2,330
No Hedge Designation [Member] | Rate-Lock Mortgage Loan Commitments [Member] | Net Gains on Mortgage Loans [Member]
Effect of derivative financial instruments on the condensed consolidated financial statements of operations [Abstract]
Gain (Loss) Recognized in Income	(3,822)	4,320
No Hedge Designation [Member] | Mandatory Commitments to Sell Mortgage Loans [Member] | Net Gains on Mortgage Loans [Member]
Effect of derivative financial instruments on the condensed consolidated financial statements of operations [Abstract]
Gain (Loss) Recognized in Income	1,837	(1,954)
No Hedge Designation [Member] | Interest-Rate Cap Agreements [Member] | Interest Expense [Member]
Effect of derivative financial instruments on the condensed consolidated financial statements of operations [Abstract]
Gain (Loss) Recognized in Income	15	(35)
No Hedge Designation [Member] | Purchased Options [Member] | Interest Expense [Member]
Effect of derivative financial instruments on the condensed consolidated financial statements of operations [Abstract]
Gain (Loss) Recognized in Income	18	(104)
No Hedge Designation [Member] | Written Options [Member] | Interest Expense [Member]
Effect of derivative financial instruments on the condensed consolidated financial statements of operations [Abstract]
Gain (Loss) Recognized in Income	(18)	103
No Hedge Designation [Member] | Fixed Income Interest Rate [Member] | Interest Rate Swap [Member] | Interest Income [Member]
Effect of derivative financial instruments on the condensed consolidated financial statements of operations [Abstract]
Gain (Loss) Recognized in Income	3,275	(8,173)
No Hedge Designation [Member] | Fixed Income Interest Rate [Member] | Interest Rate Swap [Member] | Interest Expense [Member]
Effect of derivative financial instruments on the condensed consolidated financial statements of operations [Abstract]
Gain (Loss) Recognized in Income	118	0
No Hedge Designation [Member] | Variable Income Interest Rate [Member] | Interest Rate Swap [Member] | Interest Income [Member]
Effect of derivative financial instruments on the condensed consolidated financial statements of operations [Abstract]
Gain (Loss) Recognized in Income	$ (3,275)	$ 8,173