Related Party Transactions (Details Textual) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Related Party Transactions (Additional Textual) [Abstract]
Related party transaction, revenues from transactions with related party	$ 4.1	$ 0.3	$ 10.2	$ 1.3
Receivables due from BGP	$ 5.2		$ 5.2
Corporate Joint Venture [Member]
Related Party Transactions (Textual) [Abstract]
Company's outstanding common stock owned by BGP	15.30%		15.30%