Securities (Other Securities) (Details) (USD $)	3 Months Ended	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Investments, All Other Investments [Abstract]
Securities transferred from available for sale to held to maturity, at fair value	$ 26,800,000	$ 180,900,000	$ 25,162,000	$ 179,528,000	$ 0
FHLB stock	$ 14,300,000us-gaap_FederalHomeLoanBankStock	$ 15,600,000us-gaap_FederalHomeLoanBankStock	$ 14,300,000us-gaap_FederalHomeLoanBankStock	$ 15,600,000us-gaap_FederalHomeLoanBankStock

Federal Home Loan Bank (FHLB) stock represents an equity interest in a FHLB. It does not have a readily determinable fair value because its ownership is restricted and it lacks a market (liquidity).

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 325

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6478792&loc=d3e63345-112809

Name:	us-gaap_FederalHomeLoanBankStock
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant