Financial Information (Schedule of Accounting Changes) (Details) (USD $)	3 Months Ended	12 Months Ended
	Mar. 31, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
New Accounting Pronouncement or Change in
Other assets	$ 1,429,704,000	$ 1,385,572,000
Other liabilities	628,420,000	649,359,000
Undivided profits	716,540,000	851,585,000
Other expense	18,483,000
Provision/(benefit) for income taxes	20,066,000
Net income/(loss) available to common shareholders	45,616,000
Diluted income/(loss) per share	$ 0.19
Accounting Standards Update 2014-01 [Member]
New Accounting Pronouncement or Change in
Other assets	(5,153,000)	(4,700,000)	(5,340,000)
Other liabilities	6,472,000	4,678,000	7,034,000
Undivided profits	(11,625,000)	(9,378,000)	(12,374,000)
Other expense	(2,170,000)	(8,680,000)	(10,082,000)	(14,177,000)
Provision/(benefit) for income taxes	1,421,000	5,684,000	12,780,000	13,234,000
Net income/(loss) available to common shareholders	$ 749,000	$ 2,996,000	$ (2,698,000)	$ 943,000
Diluted income/(loss) per share	$ 0	$ 0.01	$ (0.01)	$ 0