Fair Value Measurements Notional Amount of Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Notional Disclosures [Abstract]
Best efforts contracts and related committed IRLCs	$ 6,607	$ 2,625
Uncommitted IRLCs	66,875	46,339
FMBSs related to uncommitted IRLCs	66,000	46,000
Best efforts contracts and related mortgage loans held for sale	125,348	100,152
FMBSs related to mortgage loans held for sale	33,000	27,000
Mortgage loans held for sale covered by FMBSs	$ 32,870	$ 26,690