DEBT - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Debt Instrument [Line Items]
Bank loan guaranteed on behalf of Shiraishi	$ 6.0
Notes receivable extended to Shiraishi	15.2
Guarantees
Debt Instrument [Line Items]
Debt maturity period	2012-05
$1 billion revolver weighted average rate 1.74%, due in 2016
Debt Instrument [Line Items]
Maximum borrowing capacity of line of credit facility	1,000	1,000
Debt maturity period	2016-09
Senior letters of credit facility, committed to outstanding letters of credit	140.5	159.1
Senior letters of credit facility, unused portion	382.2	313.0
$100 million Private Placement notes 5.64%, due in 2015
Debt Instrument [Line Items]
Debt maturity period	2015-04
Long-term debt, face amount	100.0	100.0
$175 million Private Placement notes 3.89%, due in 2017
Debt Instrument [Line Items]
Debt maturity period	2017-10
Long-term debt, face amount	175.0	175.0
$225 million Private Placement notes 4.47%, due in 2020
Debt Instrument [Line Items]
Debt maturity period	2020-10
Long-term debt, face amount	$ 225.0	$ 225.0