Fair Value Measurements Quantitiative Information about Level 3 Non-Recurring Assets (Details) - Fair Value, Measurements, Nonrecurring [Member] - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Loans Receivable, Fair Value Disclosure	[1]	$ 1,835	$ 0
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Loans Receivable, Fair Value Disclosure	[1]	$ 1,835
Loans Receivable [Member] | Weighted Average [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Fair Value Inputs, Discount Rate		14.00%
Fair Value Inputs, Comparability Adjustments		16.00%
Loans Receivable [Member] | Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Fair Value Inputs, Discount Rate		0.00%
Fair Value Inputs, Comparability Adjustments		0.00%
Loans Receivable [Member] | Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Fair Value Inputs, Discount Rate		24.00%
Fair Value Inputs, Comparability Adjustments		26.00%

[1] Collateral-dependent impaired loans held at March 31, 2018 that had write-downs in fair value or whose specific reserve changed during the first three months of 2018.