Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Net income	$ 41,718	$ 49,970	$ 89,105	$ 95,603
Other comprehensive income:
Unrealized appreciation (depreciation) of available for sale investment securities during the period, net of income taxes of $(1,023), $(191), $1,489 and $471, respectively	(1,742)	(333)	2,548	801
Valuation allowance on investment securities' deferred tax asset during the period	(1,086)	(915)	867	(256)
Pension and postretirement benefits, net of income taxes of $526, $237, $1,047 and $432, respectively	891	436	1,548	778
Reclassification adjustment for amounts included in net income, net of income taxes of $(62), $(730), $(623), and $(730)	(107)	(1,256)	(1,073)	(1,256)
Comprehensive income	$ 39,674	$ 47,902	$ 92,995	$ 95,670