Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Consolidated Statements of Comprehensive Income
Net income	$ 48,058	$ 74,586	$ 182,616	$ 232,438
Other comprehensive income:
Unrealized depreciation of available for sale investment securities during the period, net of income tax benefit of $(5), $(11), $0 and $(9), respectively	(1,321)	(4,962)	(4,485)	(3,491)
Pension and postretirement benefits, net of income tax expense of $526, $186, $1,477 and $558, respectively	888	315	2,764	947
Comprehensive income	$ 47,625	$ 69,939	$ 180,895	$ 229,894