Impairment of Long-Lived Assets and Goodwill (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2015	Mar. 31, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Impairment expense	$ 0		$ 0	$ 25,523	$ 0
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