CONDENSED CONSOLIDATED STATEMENTS OF INCOME Net Income Per Unit: (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Net Income per Unit:
Cash distribution declared and paid to common units	$ 0.10	$ 0.5325
Cash distribution declared and paid to class B units	$ 0.00	$ 0.30
Common Units
Net income per unit:
Net income per unit	$ 0.44	$ 0.42
Weighted-average number of units outstanding:
Weighted-average units outstanding (in units)	243.3	207.7
Class B Units
Net income per unit:
Net income per unit	$ 0.00	$ 0.19
Weighted-average number of units outstanding:
Weighted-average units outstanding (in units)	0	22.9