Investments (Narrative) (Details) (USD $)	3 Months Ended
	Mar. 31, 2014 investments	Dec. 31, 2013
Investments [Abstract]
Securities gains (losses)	$ 0
Unrealized Losses Related to Marketability of Securities or Issuer's Ability to Honor Redemption Obligations	0	0
Fair Value, 12 months or more in unrealized loss position	23,622,000	56,830,000
Investment securities, aggregate unrealized loss, continuous unrealized losses of more than 12 months	800,000
Number of investments in continuous unrealized loss position for more than twelve months	16
Investment value deemed to be OTTI	0
Investment securities, aggregate carrying value, pledged as collateral	$ 2,780,000,000	$ 2,750,000,000