Securities - Narrative (Details) (USD $)	3 Months Ended		12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Available-for-sale Securities, Gross Realized Gain (Loss) [Abstract]
Net realized gain on AFS securities	$ 2,500,000	$ 11,000
Realized gains	2,500,000	2,900,000
Realized losses	54,000	2,900,000
Held-to-maturity Securities, Other Disclosure Items [Abstract]
Proceeds from sale of held-to-maturity securities	0		0
Pledged Financial Instruments, Not Separately Reported, Securities	$ 1,090,000,000		$ 1,120,000,000