Fair Value Measurements Notional Amount of Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Notional Disclosures [Abstract]
Best efforts contracts and related committed IRLCs	$ 1,445	$ 5,823
Uncommitted IRLCs	87,340	76,117
FMBSs related to uncommitted IRLCs	88,000	83,000
Best efforts contracts and related mortgage loans held for sale	6,125	14,285
FMBSs related to mortgage loans held for sale	144,000	150,000
Mortgage loans held for sale covered by FMBSs	$ 144,411	$ 149,980