Fair Value Measurements (Details 6) $ in Thousands	Dec. 31, 2017 USD ($)
Aggregate Fair Value
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Mortgage loans held for sale	$ 108,316
Past due loans of 90 days or more	0
Nonaccrual loans	0
Aggregate Unpaid Principal Balance
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Mortgage loans held for sale	104,820
Past due loans of 90 days or more	0
Nonaccrual loans	0
Difference
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Mortgage loans held for sale	3,496
Past due loans of 90 days or more	0
Nonaccrual loans	$ 0