Investments (Narrative) (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016 USD ($) security	Sep. 30, 2015 USD ($)	Sep. 30, 2016 USD ($) security	Sep. 30, 2015 USD ($)	Dec. 31, 2015 security
Investments [Abstract]
Gross gains on investments	$ 1,400	$ 76	$ 2,100	$ 6,000
Gross losses on investments	300	48	500	100
Proceeds from sale of investment securities	$ 5,400	800	$ 21,300	17,700
Number of debt security positions, greater than 12 months | security	33		33		39
Other-than-temporary impairments		$ 363	$ 2,888	$ 2,193