Investments (Narrative) (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019 USD ($) security	Jun. 30, 2018 USD ($)	Jun. 30, 2019 USD ($) security	Jun. 30, 2018 USD ($)	Dec. 31, 2018 security
Schedule of Available-for-sale Securities [Line Items]
Gross gains on investments	$ 200	$ 500	$ 4,400	$ 600
Gross losses on investments	100	100	200	200
Proceeds from sale of investment securities	$ 100	$ 14,200	7,000	$ 14,200
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Number of Positions [Abstract]
Other-than-temporary impairment			$ 0
Debt Securities [Member]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Number of Positions [Abstract]
Number of debt securities with unrealized loss | security	173		173		328
Number of debt securities with unrealized loss, less than 12 months | security	117		117		221
Number of debt securities with unrealized loss, greater than 12 months | security	56		56		107