Borrowed Funds (FHLB Borrowings, Bank Notes, Senior Debt and Subordinated Debt) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Borrowed Funds	$ 37,195,000	$ 60,263,000
Total FHLB, Senior and Sub Debt	34,174,000	51,485,000
Parent Company
Debt Instrument [Line Items]
Borrowed Funds	10,583,000	9,825,000
Bank
Debt Instrument [Line Items]
Borrowed Funds	23,591,000	41,660,000
Senior Notes | Parent Company
Debt Instrument [Line Items]
Borrowed Funds	9,573,000	8,843,000
Senior Notes | Bank
Debt Instrument [Line Items]
Borrowed Funds	$ 14,698,000	20,167,000
Senior Notes | Maximum | Parent Company
Debt Instrument [Line Items]
Stated interest rate	3.50%
Senior Notes | Maximum | Bank
Debt Instrument [Line Items]
Stated interest rate	3.50%
Senior Notes | Minimum | Parent Company
Debt Instrument [Line Items]
Stated interest rate	2.20%
Senior Notes | Minimum | Bank
Debt Instrument [Line Items]
Stated interest rate	0.00%
Subordinated Debt | Parent Company
Debt Instrument [Line Items]
Borrowed Funds	$ 805,000	777,000
Stated interest rate	3.90%
Subordinated Debt | Bank
Debt Instrument [Line Items]
Borrowed Funds	$ 5,393,000	5,152,000
Subordinated Debt | Maximum | Bank
Debt Instrument [Line Items]
Stated interest rate	4.20%
Subordinated Debt | Minimum | Bank
Debt Instrument [Line Items]
Stated interest rate	2.70%
Junior Subordinated Debt | Parent Company
Debt Instrument [Line Items]
Borrowed Funds	$ 205,000	205,000
Stated interest rate	0.80%
FHLB | Bank
Debt Instrument [Line Items]
Borrowed Funds	$ 3,500,000	$ 16,341,000
FHLB | Maximum | Bank
Debt Instrument [Line Items]
Stated interest rate	0.59%
FHLB | Minimum | Bank
Debt Instrument [Line Items]
Stated interest rate	0.32%