Condensed Consolidated Statements of Comprehensive Income (Parenthetical) (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Statement of Income and Comprehensive Income [Abstract]
Net unrealized gain (loss) on cash flow hedges, tax	$ 21	$ 773	$ 374	$ 1,018
Net unrealized loss on investment securities, tax	377	2,012	618	2,722
Amortization of pension and postretirement costs, tax	$ 6,755	$ 4,825	$ 20,221	$ 14,658