Impairment of Long-Lived Assets and Goodwill (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Mar. 31, 2015	Jun. 30, 2015
Impairment expense		$ 25,523
Southwest Segment | Appleby
Impairment expense		22,800
Impairment related to intangibles		16,800
Impairment related to property, plant and equipment		6,000
Western Oklahoma Reporting Unit | Southwest Segment
Goodwill impairment charge	$ 2,700
Other reporting units
Goodwill impairment charge		$ 0