Annual report pursuant to Section 13 and 15(d)

Supplemental Information to Consolidated Combined Financial Statements (Details)

v2.4.0.6
Supplemental Information to Consolidated Combined Financial Statements (Details) (USD $)
In Thousands, except Per Share data, unless otherwise specified
3 Months Ended 12 Months Ended
Dec. 31, 2012
Sep. 30, 2012
Jun. 30, 2012
Mar. 31, 2012
Dec. 31, 2011
Sep. 30, 2011
Jun. 30, 2011
Mar. 31, 2011
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Quarterly Financial Information Disclosure [Abstract]                      
Revenues $ 67,300 $ 66,308 $ 61,396 $ 69,323 $ 70,824 $ 64,907 $ 73,609 $ 74,450 $ 264,327 $ 283,790 $ 399,282
Income from operations 19,602 772 18,275 24,891 37,044 29,523 36,932 41,127 63,540 144,626 280,797
Net loss $ (63,521) $ (42,422) $ (24,861) $ (19,332) $ (7,463) $ (14,479) $ (6,868) $ (2,209) $ (150,136) $ (31,019) $ 107,568
Net income (loss) per common unit - basic and diluted $ (0.06) $ 0.04 $ 0.17 $ 0.23 $ 0.30 $ 0.29 $ 0.32 $ 0.35   $ 1.23 $ 1.70