Summary of Significant Accounting Policies (Tables)

9 Months Ended

Sep. 30, 2013

Summary of Significant Accounting Policies

Schedule of fair value hierarchy of assets and liabilities measured on recurring basis

	Assets and (Liabilities) at Fair Value
	September 30, 2013										December 31, 2012
	Total			Level 1		Level 2			Level 3		Total			Level 1		Level 2			Level 3
	(in thousands)
Liabilities under derivative instruments	$	(301	)	$	—	$	(301	)	$	—	$	(1,690	)	$	—	$	(1,690	)	$	—
Total	$	(301	)	$	—	$	(301	)	$	—	$	(1,690	)	$	—	$	(1,690	)	$	—

Schedule of fair value hierarchy of assets measured on nonrecurring basis and gain (losses) recorded

									Total Losses
	Assets at Fair Value (in thousands)								Nine Months Ended
	Total		Level 1		Level 2		Level 3		September 30, 2013
									(in thousands)
Balance at September 30, 2013
Equipment held for sale	$	31,506	$	—	$	29,839	$	1,667	$	(6,268	)
Total	$	31,506	$	—	$	29,839	$	1,667	$	(6,268	)

									Total Losses
	Assets at Fair Value (in thousands)								Twelve Months Ended
	Total		Level 1		Level 2		Level 3		December 31, 2012
									(in thousands)
Balance at December 31, 2012
Equipment held for sale	$	23,607	$	—	$	23,384	$	223	$	(5,874	)
Total	$	23,607	$	—	$	23,384	$	223	$	(5,874	)