Earnings Per Share - Schedule of Allocations of Earnings (Parenthetical) (Detail) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2013
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Redemption of partner units	77.4
Global Partnership Restructuring Program [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Redemption of partner units	77.4	77.4