Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Net income	$ 196,228	$ 331,491	$ 39,972
Other comprehensive loss, before tax:
Foreign currency translation adjustments	(2,257)	(4,786)	162
Available-for-sale securities:
Unrealized gain on investments	921	1,513	5,169
Reclassification of net realized gain on investments to net income	(2,379)	(2,531)	(3,493)
Derivative financial instruments:
Unrealized loss on derivatives	(262)	(2,766)	(628)
Reclassification of net realized loss/(gain) on derivatives to net income	3,037	(12)	985
Defined benefit pension and post-retirement plans:
Net actuarial loss	(60,539)	(213,701)	(42,368)
Amortization of transition asset, prior service cost and net actuarial loss	16,377	7,320	2,193
Other comprehensive loss before tax	(45,102)	(214,963)	(37,980)
Income tax expense related to items of other comprehensive loss			644
Other comprehensive loss	(45,102)	(214,963)	(38,624)
Comprehensive income	$ 151,126	$ 116,528	$ 1,348