Condensed Consolidated Statements of Comprehensive Income (Loss) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Net income	$ 53,518	$ 118,109	$ 286,268	$ 195,265
Other comprehensive income (loss):
Unrealized gain on available for sale securities	66	(6)	95	(6)
Net gain (loss) on pension and other postretirement benefits	232	324	449	216
Total other comprehensive income (loss)	298	318	544	210
Comprehensive income	$ 53,816	$ 118,427	$ 286,812	$ 195,475