Certificates and Other Time Deposits (Narrative) (Details) (USD $)	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Certificates and Other Deposits [Abstract]
Value of Certificates Disclosed, Equal or Greater Than	$ 100,000
Time Deposits, $100,000 or More	716,500,000us-gaap_TimeDeposits100000OrMore	882,400,000us-gaap_TimeDeposits100000OrMore	489,900,000us-gaap_TimeDeposits100000OrMore
Interest Expense, Time Deposits, $100,000 or More	$ 3,800,000	$ 4,500,000	$ 3,800,000

The aggregate amount of domestic and foreign time deposit liabilities (including certificates of deposits, individual retirement accounts and open accounts) in denominations of $100,000 or more.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 405

-Section 50

-Paragraph 1

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6479006&loc=d3e64164-112818

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Industry Guide

-Number 3

-Section V

-Paragraph A

-Subparagraph 4

Name:	us-gaap_TimeDeposits100000OrMore
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant