Securities - Schedule of Net Gains and Losses on Equity Investments Recognized in Earnings and Portion of Unrealized Gains and Losses for Period that Relates to Equity Investments (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($)
Investments Debt And Equity Securities [Abstract]
Net gains (losses) recognized in equity securities during the period	$ 40
Less: Net gains (losses) realized on the sale of equity securities during the period	40
Unrealized gains (losses) recognized in equity securities held at reporting date	$ 40