NOTES PAYABLE - Additional Information (Detail)	Feb. 29, 2012 series	Mar. 31, 2012 1.47% yen-denominated Samurai notes due July 2014 JPY (¥)	Dec. 31, 2011 1.47% yen-denominated Samurai notes due July 2014 JPY (¥)	Mar. 31, 2012 1.84% yen-denominated Samurai notes due July 2016 JPY (¥)	Dec. 31, 2011 1.84% yen-denominated Samurai notes due July 2016 JPY (¥)	Mar. 31, 2012 Variable interest rate yen-denominated Samurai notes due July 2014 JPY (¥)	Dec. 31, 2011 Variable interest rate yen-denominated Samurai notes due July 2014 JPY (¥)	Jul. 31, 2011 Variable interest rate yen-denominated Samurai notes due July 2014 JPY (¥)	Feb. 29, 2012 Senior Notes USD ($)	Mar. 31, 2012 2.65% senior notes due February 2017 USD ($)	Mar. 31, 2012 2.65% senior notes due February 2017 JPY (¥)	Mar. 31, 2012 4.00% senior notes due February 2022 USD ($)	Mar. 31, 2012 4.00% senior notes due February 2022 JPY (¥)	Mar. 31, 2012 6.45% senior notes due August 2040 USD ($)	Dec. 31, 2011 6.45% senior notes due August 2040 USD ($)	Mar. 31, 2012 3.45% senior notes due August 2015	Dec. 31, 2011 3.45% senior notes due August 2015	Mar. 31, 2012 6.90% senior notes due December 2039 USD ($)	Dec. 31, 2011 6.90% senior notes due December 2039 USD ($)	Mar. 31, 2012 8.50% senior notes due May 2019	Dec. 31, 2011 8.50% senior notes due May 2019	Mar. 31, 2012 2.26% yen-denominated Uridashi notes due September 2016 JPY (¥)	Dec. 31, 2011 2.26% yen-denominated Uridashi notes due September 2016 JPY (¥)	Mar. 31, 2012 1.87% yen-denominated Samurai notes due June 2012 JPY (¥)	Dec. 31, 2011 1.87% yen-denominated Samurai notes due June 2012 JPY (¥)	Mar. 31, 2012 Notes Payable USD ($)
Debt Instrument [Line Items]
Number of series of senior notes issued through a U.S. public debt offering (in series)	2
Notes payable, principal amount		¥ 28,700,000,000	¥ 28,700,000,000	¥ 15,800,000,000	¥ 15,800,000,000	¥ 5,500,000,000	¥ 5,500,000,000	¥ 5,500,000,000	$ 750,000,000	$ 400,000,000		$ 350,000,000		$ 450,000,000	$ 450,000,000			$ 400,000,000	$ 400,000,000			¥ 8,000,000,000	¥ 8,000,000,000	¥ 26,600,000,000	¥ 26,600,000,000
Notes payable, effective principal amount											30,900,000,000		27,000,000,000
Notes payable, interest rate		1.47%	1.47%	1.84%	1.84%	1.35%	1.34%			2.65%	2.65%	4.00%	4.00%	6.45%	6.45%	3.45%	3.45%	6.90%	6.90%	8.50%	8.50%	2.26%	2.26%	1.87%	1.87%
Notes payable, effective interest rate								1.475%		1.22%	1.22%	2.07%	2.07%
Notes payable, debt default, amount																										$ 0