Disclosures About Fair Value of Financial Instruments - Reconciliation of beginning and ending balances of recurring fair value measurements using significant unobservable (Details 1) (Fair Value, Measurements, Recurring, Available-for-Sale Securities, USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Fair Value, Measurements, Recurring | Available-for-Sale Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 1,268	$ 1,197
Accretion	10	12
Total realized and unrealized gains and losses
Unrealized gains included in other comprehensive income	80	128
Settlements, including pay downs	(36)	(69)
Ending balance	1,322	1,268
Total gains or losses for the period included in net income attributable to the change in unrealized gains or losses related to assets and liabilities still held at the reporting date