NOTES PAYABLE - Additional Information (Detail)	1 Months Ended	12 Months Ended			1 Months Ended			1 Months Ended			1 Months Ended								1 Months Ended					1 Months Ended			1 Months Ended					1 Months Ended			1 Months Ended			1 Months Ended			1 Months Ended			1 Months Ended	12 Months Ended			1 Months Ended			12 Months Ended
	Jun. 30, 2012	Dec. 31, 2012 JPY (¥)	Feb. 29, 2012 series	Jul. 31, 2011 series	Jul. 31, 2011 1.47% yen-denominated Samurai notes due July 2014 JPY (¥)	Dec. 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 (¥)	Jul. 31, 2011 1.84% yen-denominated Samurai notes due July 2016 JPY (¥)	Dec. 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 (¥)	Jul. 31, 2011 Variable interest rate yen-denominated Samurai notes due July 2014 JPY (¥)	Dec. 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 (¥)	Dec. 31, 2012 3.60% yen-denominated loan due July 2015 JPY (¥)	Dec. 31, 2011 3.60% yen-denominated loan due July 2015 JPY (¥)	Dec. 31, 2012 3.00% yen-denominated loan due August 2015 JPY (¥)	Dec. 31, 2011 3.00% yen-denominated loan due August 2015 JPY (¥)	Feb. 29, 2012 Senior Notes USD ($)	Jul. 31, 2012 2.65% senior notes due February 2017 USD ($)	Feb. 29, 2012 2.65% senior notes due February 2017 USD ($)	Feb. 29, 2012 2.65% senior notes due February 2017 JPY (¥)	Dec. 31, 2012 2.65% senior notes due February 2017 USD ($)	Jul. 31, 2011 Yen Denominated Samurai Notes [Member] JPY (¥)	Feb. 29, 2012 4.00% senior notes due February 2022 USD ($)	Feb. 29, 2012 4.00% senior notes due February 2022 JPY (¥)	Dec. 31, 2012 4.00% senior notes due February 2022 USD ($)	Oct. 31, 2012 5.50% subordinated notes due September 2052 USD ($)	Oct. 31, 2012 5.50% subordinated notes due September 2052 JPY (¥)	Sep. 30, 2012 5.50% subordinated notes due September 2052 USD ($)	Dec. 31, 2012 5.50% subordinated notes due September 2052 USD ($)	Dec. 31, 2012 5.50% subordinated notes due September 2052 JPY (¥)	Aug. 31, 2010 6.45% senior notes due August 2040 USD ($)	Dec. 31, 2012 6.45% senior notes due August 2040 USD ($)	Dec. 31, 2011 6.45% senior notes due August 2040	Aug. 31, 2010 3.45% senior notes due August 2015 USD ($)	Dec. 31, 2012 3.45% senior notes due August 2015	Dec. 31, 2011 3.45% senior notes due August 2015	Dec. 31, 2009 6.90% senior notes due December 2039 USD ($)	Dec. 31, 2012 6.90% senior notes due December 2039 USD ($)	Dec. 31, 2011 6.90% senior notes due December 2039	May 31, 2009 8.50% senior notes due May 2019 USD ($)	Dec. 31, 2012 8.50% senior notes due May 2019	Dec. 31, 2011 8.50% senior notes due May 2019	Sep. 30, 2006 2.26% yen-denominated Uridashi notes due September 2016 JPY (¥)	Dec. 31, 2009 2.26% yen-denominated Uridashi notes due September 2016 JPY (¥)	Dec. 31, 2012 2.26% yen-denominated Uridashi notes due September 2016 JPY (¥)	Dec. 31, 2011 2.26% yen-denominated Uridashi notes due September 2016 JPY (¥)	Jun. 30, 2012 1.87% yen-denominated Samurai notes paid June 2012 USD ($)	Jun. 30, 2012 1.87% yen-denominated Samurai notes paid June 2012 JPY (¥)	Jun. 30, 2007 1.87% yen-denominated Samurai notes paid June 2012 JPY (¥)	Dec. 31, 2009 1.87% yen-denominated Samurai notes paid June 2012 JPY (¥)	Dec. 31, 2011 1.87% yen-denominated Samurai notes paid June 2012 JPY (¥)	Dec. 31, 2012 Notes Payable USD ($)	Dec. 31, 2011 Notes Payable USD ($)
Debt Instrument [Line Items]
Notes payable, principal amount					¥ 28,700,000,000	¥ 28,700,000,000	¥ 28,700,000,000	¥ 15,800,000,000	¥ 15,800,000,000	¥ 15,800,000,000	¥ 5,500,000,000	¥ 5,500,000,000	¥ 5,500,000,000	¥ 10,000,000,000	¥ 10,000,000,000	¥ 5,000,000,000	¥ 5,000,000,000	$ 750,000,000	$ 250,000,000	$ 400,000,000		$ 650,000,000	¥ 50,000,000,000	$ 350,000,000		$ 350,000,000	$ 50,000,000		$ 450,000,000	$ 450,000,000		$ 450,000,000	$ 450,000,000		$ 300,000,000			$ 400,000,000	$ 400,000,000		$ 850,000,000			¥ 10,000,000,000		¥ 8,000,000,000	¥ 8,000,000,000			¥ 30,000,000,000		¥ 26,600,000,000
Notes payable, interest rate					1.47%	1.47%	1.47%	1.84%	1.84%	1.84%	1.475%	1.34%	1.34%	3.60%	3.60%	3.00%	3.00%		2.65%	2.65%	2.65%	2.65%		4.00%	4.00%	4.00%	5.50%	5.50%	5.50%	5.50%	5.50%		6.45%	6.45%		3.45%	3.45%		6.90%	6.90%		8.50%	8.50%			2.26%	2.26%					1.87%
Debt instrument maturity period					3 years			5 years			3 years								5 years	5 years	5 years			10 years	10 years				40 years			30 years			5 years			30 years			10 years			10 years						5 years
Minimum prinicipal amount outstanding following partial redemption																														25,000,000
Debt instrument effective principal amount after cross currency swap																					30,900,000,000				27,000,000,000			3,900,000,000			35,300,000,000
Derivative instrument maturity period																											5 years	5 years	5 years
Number of series of senior notes issued through a U.S. public debt offering (in series)			2	3
Notes payable, effective interest rate												1.475%								1.22%	1.22%			2.07%	2.07%		4.42%	4.42%		4.41%	4.41%
Extinguishment of notes																																													2,000,000,000						3,400,000,000
Samurai notes redeemed upon maturity																																																337,000,000	26,600,000,000
Principal payments under debt obligations																																													1,400,000,000						2,500,000,000
Gain on extinguishment of debt																																													600,000,000						900,000,000
Line of credit facility term	364 days
Line of credit facility, maximum borrowing capacity		50,000,000,000
Line of credit facility, interest rate description	Borrowings will bear interest at LIBOR plus the applicable margin of 1.025%
Line of credit facility, commitment fee percentage		0.10%
Line of credit facility, amount outstanding		0
Extended line of credit facility term	364 days
Notes payable, debt default, amount																																																					$ 0	$ 0