Fair Value Measurements Fair Value Nonrecurring Basis (Details) - Fair Value, Measurements, Nonrecurring [Member] - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2018	[1]	Jun. 30, 2017	[2]	Jun. 30, 2018	[1]	Jun. 30, 2017	[2]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans Receivable, Fair Value Disclosure	$ 3,051		$ 1,040		$ 3,051		$ 1,040
Loans Receivable, Fair Value Adjustment	(711)		(221)		(927)		(219)
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans Receivable, Fair Value Disclosure	0		0		0		0
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans Receivable, Fair Value Disclosure	0		0		0		0
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans Receivable, Fair Value Disclosure	$ 3,051		$ 1,040		$ 3,051		$ 1,040

[1] Collateral-dependent impaired loans held at June 30, 2018 that had write-downs in fair value or whose specific reserve changed during the first six months of 2018.

[2] Collateral-dependent impaired loans held at June 30, 2017 that had write-downs in fair value or whose specific reserve changed during the first six months of 2017.