Assets Held-for-Sale and Discontinued Operations (Details 2) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Discontinued operations
Undiscounted contractual commitments	$ 43,200		$ 43,200
Liability related to discontinued operation	25,000		25,000		$ 40,200
Current liability to discontinued operations	7,823		7,823		$ 19,602
Income (loss) from discontinued operations
Income (loss) from discontinued operations, net of tax	5,025	$ (1,032)	4,208	$ 483
Oil and Gas
Operating revenues
Operating revenues	855	3,471	2,305	8,528
Income (loss) from discontinued operations
Income (loss) from discontinued operations	(1,129)	(1,082)	(2,515)	1,536
Less: Impairment charges or other (gains) and losses on sale of wholly owned assets and obligations	1,031	409	1,031	1,411
Less: Income tax expense (benefit)	(7,185)	(459)	(7,754)	(358)
Income (loss) from discontinued operations, net of tax	$ 5,025	$ (1,032)	$ 4,208	$ 483