CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME
Net unrealized gain (loss), tax benefit (expense)	$ (26)	$ 105	$ (624)	$ 67
Reclassification of net realized loss, tax benefit	1,261	2,824	2,584	6,124
Pension and other postretirement benefits activity, tax expense	$ 845	$ 449	$ 128	$ (182)