Investments (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Investments [Abstract]
Other trading securities unrealized holding gain (loss) (less than for 2015 periods)	$ 100	$ (600)	$ (100)	$ (500)
Investment [Line Items]
% of Total			100.00%		100.00%
Gross unrealized losses related to high or highest quality securities	11,300		$ 11,300		$ 4,000
Gross unrealized losses related to other than high or highest quality securities	3,600		3,600		3,100
Twelve months or more Unrealized Losses	2,156		2,156		$ 1,152
All other corporate securities
Investment [Line Items]
Securities Loaned, Including Not Subject To Master Netting Arrangement And Assets Other Than Securities Transferred	$ 5,000		$ 5,000
California
Investment [Line Items]
% of Total			18.00%
Texas
Investment [Line Items]
% of Total			12.00%