Accumulated Other Comprehensive Loss (Textual) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2012
Accumulated Other Comprehensive Loss (Textual) [Abstract]
Net unrealized gains on investment securities-available-for-sale, tax expense	$ (486)	$ 2,301	$ 2,051
Pension and other postretirement benefits adjustment, tax benefit	$ 18,394	$ 19,058	$ 15,062

Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Tax Expense

No definition available.

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Balance Type:	credit
Period Type:	instant