Investment Securities (Narrative) (Details) (USD $)	3 Months Ended
	Mar. 31, 2014 securities	Dec. 31, 2013
Investments [Abstract]
Pledged to secure deposits	$ 2,140,000,000	$ 2,330,000,000
Securities in a loss position for less than twelve months	71
Securities in a loss position for more than 12 months	5
Other-than-temporary impairment charges	$ (88,000)