Investments - Equity Securities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Equity Securities, FV-NI, Gain (Loss) [Abstract]
Cost	$ 4,016		$ 3,993
Gross Gains	60		11
Gross Losses	(19)		(72)
Fair Value	4,057		$ 3,932
Unrealized Gain (Loss) on Equity Securities [Abstract]
Recognized net gains (losses) on equity securities still held	$ 100	$ (100)