Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Statement of Financial Position [Abstract]
Trade accounts receivable, allowance	$ 1,190	$ 297
Other, accumulated amortization of debt issuance costs	10,186	3,326
Intangible assets, accumulated amortization	44,856	15,584
Deferred revenues, related party amounts	41	8,765
Series A convertible redeemable preferred units, redemption amount	$ 84,773	$ 83,891
Common units, authorized	161,233,046	138,255,919
Common units, issued	157,437,608	137,281,336
Common units, outstanding	157,437,608	137,281,336