Commitments and Contingencies (Guarantees Outstanding) (Details) - Loans Sold or Securitized With Recourse - Loans Sold or Securitized with Recourse - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Guarantor obligation, maximum potential future payment [Abstract]
Expire After One Year Through Three Years	$ 587
Expire After Three Years Through Five Years	369
Expire After Five Years	24,520
Total	25,476	$ 26,198
Carrying Value	35,403	37,145
Single Family Residential
Guarantor obligation, maximum potential future payment [Abstract]
Expire After One Year Through Three Years	392
Expire After Three Years Through Five Years	369
Expire After Five Years	9,525
Total	10,286	10,526
Carrying Value	10,286	10,526
Multifamily residential
Guarantor obligation, maximum potential future payment [Abstract]
Expire After One Year Through Three Years	195
Expire After Three Years Through Five Years	0
Expire After Five Years	14,995
Total	15,190	15,672
Carrying Value	$ 25,117	$ 26,619