Net Deferred Tax Liabilities (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Schedule of Deferred Income Tax Assets and Liabilities
Property and equipment	$ 1,713.9	$ 1,651.3
Other	636.4	541.7
Total deferred tax liabilities	2,350.3	2,193.0
Property and equipment	(403.6)	(355.4)
Employee benefit plans	(362.9)	(406.3)
Intangible assets	(258.0)	(256.2)
Deferred foreign tax credits	(179.5)	(173.9)
Capital loss carryforwards	(2.8)	(26.0)
Operating loss carryforwards	(92.4)	(71.1)
Indemnification liabilities	(18.3)	(33.4)
Other	(298.3)	(312.6)
Total deferred tax assets before valuation allowance	(1,615.8)	(1,634.9)
Valuation Allowance	127.0	102.0
Net deferred tax liabilities	861.5	660.1
Deferred income taxes	1,531.1	1,344.1
Other Noncurrent Assets
Schedule of Deferred Income Tax Assets and Liabilities
Deferred tax assets	(603.6)	(606.3)
Prepaid expenses and other current assets
Schedule of Deferred Income Tax Assets and Liabilities
Deferred tax assets	$ (66.0)	$ (77.7)