Fair Value Disclosures (Details 1) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Tax-exempt asset-backed securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at Beginning of Period	$ 191,474	$ 191,844	$ 197,027	$ 95,804
Purchases / Additions	8,470	0	8,470	92,010
Sales / Reductions	(132)	(138)	(4,485)	(138)
Realized	0	0	0	0
Unrealized	(8,395)	9,633	(9,595)	13,663
Balance at End of Period	191,417	201,339	191,417	201,339
Credit risk transfer securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at Beginning of Period	8,015	10,637	11,964	0
Purchases / Additions	0	0	0	15,044
Sales / Reductions	0	0	0	0
Realized	0	0	0	(331)
Unrealized	2,938	316	(1,011)	(3,760)
Balance at End of Period	10,953	10,953	10,953	10,953
Loans Held For Sale
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at Beginning of Period	6,694	13,046	7,043	16,415
Purchases / Additions	107	0	320	0
Sales / Reductions	(780)	(2,532)	(1,464)	(6,410)
Realized	88	132	116	348
Unrealized	50	284	144	577
Balance at End of Period	$ 6,159	$ 10,930	$ 6,159	$ 10,930