Consolidated Statement of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012
Net income	$ 15,487		$ 5,051
Amortization of prior service credit included in net periodic cost, net of tax of $(870) and $(813)	(1,362)	[1]	(1,273)
Amortization of actuarial loss included in net periodic cost, net of tax of $2,246 and $1,827	3,513	[1]	2,858
Other comprehensive income, net of tax	2,151	[1]	1,585
Comprehensive income	$ 17,638		$ 6,636

[1] (a)