Accumulated Other Comprehensive Loss (Details Textual) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Accumulated Other Comprehensive Loss (Textual) [Abstract]
Net unrealized gains on investment securities-available-for-sale, tax expense	$ 2,301	$ 1,796	$ 1,786
Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Tax Expense	$ 19,058	$ 15,435	$ 9,384