Fair Value Measurements Notional Amount of Financial Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Notional Disclosures [Abstract]
Whole loan contracts and related committed IRLCs	$ 2,418	$ 2,354
Uncommitted IRLCs	302,394	208,500
FMBSs related to uncommitted IRLCs	279,000	183,000
Whole loan contracts and related mortgage loans held for sale	4,689	78,142
FMBSs related to mortgage loans held for sale	164,000	131,000
Mortgage loans held for sale covered by FMBSs	$ 160,826	$ 148,331