Other Other - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011
Short-term Debt	$ 372.2		$ 312.3
Repayments of Long-term Debt	17.5	24.2
Unrecognized Tax Benefits	82.5
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense	0.5	1.2
Northwind Holdings LLC [Member]
Repayments of Long-term Debt	15.0
Tailwind Holdings LLC [Member]
Repayments of Long-term Debt	2.5
Minimum [Member]
Unrecognized Tax Benefits Reasonably Possible Decreases Resulting from Settlements with Taxing Authorities	0
Maximum [Member]
Unrecognized Tax Benefits Reasonably Possible Decreases Resulting from Settlements with Taxing Authorities	$ 66.0