Other Noncurrent Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Other Noncurrent Assets
Deferred financing costs	$ 33,483	$ 37,807
Field inventory	5,911	5,713
Other	166	211
Other noncurrent assets	39,560	$ 43,731
Impairment of deferred financing cost	$ 4,600