Accumulated Other Comprehensive Income - Tax Effects on Each Component of Other Comprehensive Income Recognized in Statements of Comprehensive Income (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Statement Of Income And Comprehensive Income [Abstract]
Foreign currency cumulative translation adjustments, Before Tax	$ (44.4)	$ 46.1	$ 4.6
Unrealized cash flow hedge gains/(losses), Before Tax	63.6	15.2	(34.9)
Reclassification adjustments on foreign currency hedges, Before Tax	(7.8)	12.2	41.2
Unrealized gains on securities, Before Tax	0.1	0.4	0.2
Adjustments to prior service cost and unrecognized actuarial assumptions, Before Tax	50.3	20.3	(71.3)
Total Other Comprehensive Gain/(Loss), Before Tax	61.8	94.2	(60.2)
Foreign currency cumulative translation adjustments, Tax
Unrealized cash flow hedge gains/(losses), Tax	30.2	4.3	(4.3)
Reclassification adjustments on foreign currency hedges, Tax	(3.4)	8.9	16.7
Unrealized gains on securities, Tax
Adjustments to prior service cost and unrecognized actuarial assumptions, Tax	11.8	8.5	(23.0)
Total Other Comprehensive Gain/(Loss), Tax	38.6	21.7	(10.6)
Foreign currency cumulative translation adjustments, net of tax	(44.4)	46.1	4.6
Unrealized cash flow hedge gains/(losses), net of tax	33.4	10.9	(30.6)
Reclassification adjustments on foreign currency hedges, net of tax	(4.4)	3.3	24.5
Unrealized gains on securities, net of tax	0.1	0.4	0.2
Adjustments to prior service cost and unrecognized actuarial assumptions, net of tax	38.5	11.8	(48.3)
Total Other Comprehensive Income (Loss)	$ 23.2	$ 72.5	$ (49.6)