Reconciliation of Income and Expenses (Details 3) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Operating revenues	$ 43,087	$ 139,580	$ 98,023	$ 277,115
Operating expenses	442,725	103,057	1,015,677	201,307
Operating income (loss)	(399,638)	36,523	(917,654)	75,808
Other income	188	1,010	2,069	1,025
Interest expense	33	31	55	57
Income (loss) from discontinued operations before income taxes	(399,483)	37,502	(915,640)	76,776
Income taxes	(148,068)	13,621	(339,620)	27,783
Income (loss) from discontinued operations	$ (251,415)	$ 23,881	$ (576,020)	$ 48,993