Joint Venture Investment in Clean Coal (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
ASSETS
Receivables, net of allowance for doubtful accounts	$ 37,087		$ 37,087		$ 11,025
Prepaid expenses and other assets	3,011		3,011		2,888
Total property and equipment, net	43,378		43,378		44,611
LIABILITIES AND STOCKHOLDERS DEFICIT
Accounts payable to related parties	3,953		3,953		5,082
Line of credit					3,000
Deferred revenue	50,152		50,152		4,489
Deferred revenue	17,235		17,235		875
Net revenue	74,593	74,353	201,837	145,084
Subsidiary Joint Venture
ASSETS
Cash and cash equivalents	6,269		6,269		994
Receivables, net of allowance for doubtful accounts	4,021		4,021		3,275
Prepaid expenses and other assets	10,439		10,439		2,546
Total property and equipment, net	38,532		38,532		40,096
LIABILITIES AND STOCKHOLDERS DEFICIT
Accounts payable and accrued liabilities	2,179		2,179		5,728
Accounts payable to related parties	3,953		3,953		5,082
Line of credit					3,000
Deferred revenue and other liabilities					21,200
Deferred revenue	32,350		32,350		625
Deferred revenue	17,235		17,235		875
Net revenue	55,838	70,197	158,149	133,722
Net income (loss)	$ 10,892	$ (208)	$ 19,599	$ 4,544