Investment Securities - Gross Gains and Losses on Sales and Redemptions of Available for Sale Securities and Other Than Temporary Impairment Losses Recognized (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Sales and Redemptions of Available for Sale Securities:
Gross gains	$ 0	$ 843	$ 487	$ 2,134
Gross losses	0	0	0	0
Other-than-temporary impairment losses	$ 0	$ 0	$ 0	$ 0