Disclosures About Fair Value of Assets and Liabilities - Reconciliation of Beginning and Ending Balances of Recurring Fair Value Measurements using Significant Unobservable Level 3 Inputs (Details) - Fair Value, Measurements, Recurring - Available for Sale Securities - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Available for Sale Securities
Balance at beginning of the period	$ 3,966	$ 3,279	$ 3,978	$ 5,169
Included in other comprehensive income	1	48	(24)	59
Principal payments	3	3	16	(1,898)
Ending balance	$ 3,970	$ 3,330	$ 3,970	$ 3,330