Investments (Narrative) (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015 USD ($) security	Sep. 30, 2014 USD ($)	Sep. 30, 2015 USD ($) security	Sep. 30, 2014 USD ($)	Dec. 31, 2014 security
Investments [Abstract]
Gross gains on investments	$ 76,000	$ 100	$ 6,000	$ 400
Gross losses on investments	48	100	100	200
Proceeds from sale of investment securities	$ 800	$ 600	$ 17,700	$ 14,900
Number of debt security positions, greater than 12 months | security	25		25		24