Investment Securities (Debt Securities for which Credit Loss was Recognized in Income and Other Losses Recorded in Other Comprehensive Income) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Investment Securities [Abstract]
Credit losses on debt securities held, beginning of year	$ 109	$ 1,205
Reductions related to actual losses incurred
Credit losses on debt securities held, end of period	$ 109	$ 1,205