Condensed Consolidated Statements of Comprehensive Income (Parenthetical) (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Statement of Income and Comprehensive Income [Abstract]
Net unrealized gain (loss) on cash flow hedges, tax	$ 321	$ 273	$ 353	$ 245
Net unrealized loss on investment securities, tax	790	790	242	710
Amortization of pension and postretirement costs, tax	$ 6,580	$ 4,856	$ 13,466	$ 9,833