Investment Securities – Available-for-Sale Unrealized Loss Position Summary (Details) - U.S. government-sponsored mortgage-backed securities $ in Thousands	Jun. 30, 2018 USD ($) security	Dec. 31, 2017 USD ($) security
Schedule of Available-for-sale Securities [Line Items]
Less Than 12 Months Fair Value	$ 2,658	$ 2,851
Less Than 12 Months Unrealized Losses	$ 106	$ 19
Number of Securities | security	1	1
Total Fair Value	$ 2,658	$ 2,851
Total Unrealized Losses	$ 106	$ 19