Investments (Narrative) (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Net change in unrealized gains (losses) from other trading account assets	$ 100,000	$ 400,000
Net investment income	44,501,000	58,540,000
Gross unrealized losses related to high or highest quality securities	9,800,000		20,400,000
Gross unrealized losses related to other than high or highest quality securities	800,000		1,500,000
Gross unrealized losses representing declines in value of greater than 20%	0		200,000
Gross unrealized losses in a continuous loss position for less than six months	0		200,000
Twelve months or more Unrealized Losses	$ 1,474,000		$ 1,621,000