Accumulated Other Comprehensive Loss (Textual) (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014
Accumulated Other Comprehensive Loss (Textual) [Abstract]
Net unrealized gains (losses) on investment securities-available-for-sale, tax expense (benefit)	$ 505	$ (113)	$ (185)
Pension and other postretirement benefits adjustment, tax benefit	$ 16,220	$ 17,362	$ 10,318

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

No definition available.

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant