Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Consolidated Statements of Comprehensive Income
Unrealized depreciation of available for sale investment securities during the year, income tax expense (benefit)	$ 2	$ 1	$ (9)
Pension and postretirement benefits, income tax expense (benefit)	$ (3,794)	$ (16,725)	$ 17,272