Amount available for issuance under the Bank note program

No definition available.

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- Definition

The remaining balance of senior unsecured debt and subordinated debt which may be issued by the entity.

+ References

No definition available.

+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

The minimum payment required as part of a prepayment of long term debt

+ References

No definition available.

+ Details

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- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Definition

Amount of the collateral pledged in support of federal home loan bank advances outstanding.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6479118&loc=d3e64650-112822

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=6479336&loc=d3e64711-112823

+ Details

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Balance Type:	debit
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- Definition

Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.16)
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.16)
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 20, 22
-Article 5

+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

The interest rate applicable to the portion of the carrying amount of long-term borrowings outstanding as of the balance sheet date, including current maturities, which accrues interest at a set, unchanging rate.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Weighted average interest rate of long-term debt outstanding.

+ References

No definition available.

+ Details

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Long-Term Debt (Details) - USD ($)	12 Months Ended
Long-Term Debt (Details) - USD ($)	Dec. 31, 2015	Dec. 31, 2014	Jan. 31, 2016	Feb. 02, 2015	Jan. 01, 2015
Debt Instrument
Long-term debt	$ 12,349,000,000	$ 6,972,000,000
Federal Home Loan advances, collateral pledged	57,100,000,000	54,700,000,000
MUFG Americas Holdings Corporation
Debt Instrument
Long-term debt	2,932,000,000	$ 750,000,000
MUFG Americas Holdings Corporation \| Senior debt
Debt Instrument
Long-term debt	$ 1,400,000,000			$ 2,200,000,000	$ 3,600,000,000
MUFG Americas Holdings Corporation \| Senior debt \| Fixed Rate One Point Six Two Five Percent Notes Due February Two Thousand Eighteen [Member] [Domain] [Domain]
Debt Instrument
Debt instrument, Fixed interest rate (as a percent)	1.625%
MUFG Americas Holdings Corporation \| Senior debt \| Fixed Rate Two Point Two Five Percent Notes Due February Two Thousand Twenty [Member] [Domain] [Domain]
Debt Instrument
Debt instrument, Fixed interest rate (as a percent)	2.25%
MUFG Americas Holdings Corporation \| Senior debt \| Fixed Rate Three Point Five Zero Percent Notes Due June Two Thousand Twenty Two [Member]
Debt Instrument
Debt instrument, Fixed interest rate (as a percent)	3.50%	3.50%
MUFG Americas Holdings Corporation \| Senior debt \| Fixed Rate Three Point Zero Percent Notes Due February Two Thousand Twenty Five [Member] [Domain]
Debt Instrument
Debt instrument, Fixed interest rate (as a percent)	3.00%
MUFG Americas Holdings Corporation \| Senior debt \| Floating Rate Senior Notes due February 2018 [Member]
Debt Instrument
Long-term debt	$ 250,000,000	$ 0
MUFG Americas Holdings Corporation \| Senior debt \| Fixed Rate Senior Note 1.625 Percent due February 2018 [Member]
Debt Instrument
Long-term debt	450,000,000	0
MUFG Americas Holdings Corporation \| Senior debt \| Fixed Rate Senior Note 2.25 Percent due February 2022 [Member]
Debt Instrument
Long-term debt	1,000,000,000	0
MUFG Americas Holdings Corporation \| Senior debt \| Fixed Rate Senior Note 3.50 Percent due June 2022 [Member]
Debt Instrument
Long-term debt	398,000,000	398,000,000
MUFG Americas Holdings Corporation \| Senior debt \| Fixed Rate Senior Note 3.00 Percent due February 2025 [Member]
Debt Instrument
Long-term debt	498,000,000	0
MUFG Americas Holdings Corporation \| Subordinated Debt \| Floating rate subordinated debt due December 2023
Debt Instrument
Long-term debt	$ 300,000,000	$ 300,000,000
Debt instrument, weighted-average interest rate (as a percent)	1.98%	1.63%
MUFG Americas Holdings Corporation \| Subordinated Debt \| Floating rate subordinated debt due December 2023 \| LIBOR
Debt Instrument
Interest rate above variable interest rate (as a percent)	1.38%	1.38%
MUFG Americas Holdings Corporation \| Junior subordinated debt payable to trusts \| Floating rate notes ranging March 2033 to September 2036
Debt Instrument
Long-term debt	$ 36,000,000	$ 52,000,000
Debt instrument, weighted-average interest rate (as a percent)	2.21%	2.35%
MUFG Union Bank, N.A. and other subsidiaries
Debt Instrument
Long-term debt	$ 9,417,000,000	$ 6,222,000,000
Amount available for issuance under the bank note program	1,900,000,000
MUFG Union Bank, N.A. and other subsidiaries \| Minimum
Debt Instrument
Prepayment of long term debt	500,000
MUFG Union Bank, N.A. and other subsidiaries \| Maximum
Debt Instrument
Amount available for issuance under the bank note program	$ 8,000,000,000
MUFG Union Bank, N.A. and other subsidiaries \| Senior Notes [Member]
Debt Instrument
Amount available for issuance under the Bank note program	1 year
MUFG Union Bank, N.A. and other subsidiaries \| Subordinated Debt
Debt Instrument
Amount available for issuance under the Bank note program	5 years
MUFG Union Bank, N.A. and other subsidiaries \| Senior debt \| Floating Rate Senior Notes due February 2018 [Member]
Debt Instrument
Debt instrument, weighted-average interest rate (as a percent)	0.91%
MUFG Union Bank, N.A. and other subsidiaries \| Senior debt \| Floating Rate Senior Notes due February 2018 [Member] \| LIBOR
Debt Instrument
Interest rate above variable interest rate (as a percent)	0.57%
MUFG Union Bank, N.A. and other subsidiaries \| Senior debt \| Federal Home Loan Bank advances
Debt Instrument
Long-term debt	$ 500,000,000	$ 800,000,000
Debt instrument, weighted-average interest rate (as a percent)	2.50%	2.56%
MUFG Union Bank, N.A. and other subsidiaries \| Senior debt \| Fixed rate 3.00% notes due June 2016
Debt Instrument
Long-term debt	$ 700,000,000	$ 700,000,000
Debt instrument, Fixed interest rate (as a percent)	3.00%	3.00%
MUFG Union Bank, N.A. and other subsidiaries \| Senior debt \| Fixed rate 1.50% notes due September 2016
Debt Instrument
Long-term debt	$ 499,000,000	$ 499,000,000
Debt instrument, Fixed interest rate (as a percent)	1.50%	1.50%
MUFG Union Bank, N.A. and other subsidiaries \| Senior debt \| Floating rate notes due September 2016
Debt Instrument
Long-term debt	$ 500,000,000	$ 500,000,000
Debt instrument, weighted-average interest rate (as a percent)	1.35%	1.00%
MUFG Union Bank, N.A. and other subsidiaries \| Senior debt \| Floating rate notes due September 2016 \| LIBOR
Debt Instrument
Interest rate above variable interest rate (as a percent)	0.75%	0.75%
MUFG Union Bank, N.A. and other subsidiaries \| Senior debt \| Floating rate notes due May 2017
Debt Instrument
Long-term debt	$ 250,000,000	$ 250,000,000
Debt instrument, weighted-average interest rate (as a percent)	0.73%	0.63%
MUFG Union Bank, N.A. and other subsidiaries \| Senior debt \| Floating rate notes due May 2017 \| LIBOR
Debt Instrument
Interest rate above variable interest rate (as a percent)	0.40%	0.40%
MUFG Union Bank, N.A. and other subsidiaries \| Senior debt \| Fixed rate 2.125% notes due June 2017
Debt Instrument
Long-term debt	$ 499,000,000	$ 499,000,000
Debt instrument, Fixed interest rate (as a percent)	2.125%
MUFG Union Bank, N.A. and other subsidiaries \| Senior debt \| Fixed rate 2.625% notes due September 2018
Debt Instrument
Long-term debt	$ 1,000,000,000	1,000,000,000
Debt instrument, Fixed interest rate (as a percent)	2.625%
MUFG Union Bank, N.A. and other subsidiaries \| Senior debt \| Fixed Rate 2.25% notes due May 2019
Debt Instrument
Long-term debt	$ 502,000,000	499,000,000
Debt instrument, Fixed interest rate (as a percent)	2.25%
MUFG Union Bank, N.A. and other subsidiaries \| Senior debt \| Floating Rate Debt Due January 2018 Issued August 2015 [Member]
Debt Instrument
Debt instrument, weighted-average interest rate (as a percent)	1.09%
MUFG Union Bank, N.A. and other subsidiaries \| Senior debt \| Floating Rate Debt Due January 2018 Issued August 2015 [Member] \| LIBOR
Debt Instrument
Interest rate above variable interest rate (as a percent)	0.85%
MUFG Union Bank, N.A. and other subsidiaries \| Senior debt \| Floating Rate Debt Due January 2018 Issued September 2015 [Member]
Debt Instrument
Debt instrument, weighted-average interest rate (as a percent)	1.11%
MUFG Union Bank, N.A. and other subsidiaries \| Senior debt \| Floating Rate Debt Due January 2018 Issued September 2015 [Member] \| LIBOR
Debt Instrument
Interest rate above variable interest rate (as a percent)	0.87%
MUFG Union Bank, N.A. and other subsidiaries \| Senior debt \| Floating Rate Debt Due January 2018 Issued October 2015 [Member]
Debt Instrument
Debt instrument, weighted-average interest rate (as a percent)	1.27%
MUFG Union Bank, N.A. and other subsidiaries \| Senior debt \| Floating Rate Debt Due January 2018 Issued October 2015 [Member] \| LIBOR
Debt Instrument
Interest rate above variable interest rate (as a percent)	1.03%
MUFG Union Bank, N.A. and other subsidiaries \| Subordinated Debt \| Floating Rate Debt Due January 2018 Issued August 2015 [Member]
Debt Instrument
Long-term debt	$ 1,000,000,000	0
MUFG Union Bank, N.A. and other subsidiaries \| Subordinated Debt \| Floating Rate Debt Due January 2018 Issued September 2015 [Member]
Debt Instrument
Long-term debt	1,500,000,000	0
MUFG Union Bank, N.A. and other subsidiaries \| Subordinated Debt \| Floating Rate Debt Due January 2018 Issued October 2015 [Member] [Member]
Debt Instrument
Long-term debt	1,000,000,000
MUFG Union Bank, N.A. and other subsidiaries \| Subordinated Debt \| Fixed rate 5.95% notes due May 2016
Debt Instrument
Long-term debt	$ 703,000,000	$ 711,000,000
Debt instrument, Fixed interest rate (as a percent)	5.95%	5.95%
MUFG Union Bank, N.A. and other subsidiaries \| Subordinated Debt \| Floating rate notes due to BTMU June 2023
Debt Instrument
Long-term debt	$ 750,000,000	$ 750,000,000
Debt instrument, weighted-average interest rate (as a percent)	1.80%	1.45%
MUFG Union Bank, N.A. and other subsidiaries \| Subordinated Debt \| Floating rate notes due to BTMU June 2023 \| LIBOR
Debt Instrument
Interest rate above variable interest rate (as a percent)	1.20%	1.20%
MUFG Union Bank, N.A. and other subsidiaries \| Subordinated Debt \| Capital Lease Obligations
Debt Instrument
Debt instrument, weighted-average interest rate (as a percent)	4.92%	4.92%
MUFG Union Bank, N.A. and other subsidiaries \| Junior subordinated debt payable to trusts \| Capital Lease Obligations
Debt Instrument
Long-term debt	$ 14,000,000	$ 14,000,000
Subsequent Event [Member] \| MUFG Union Bank, N.A. and other subsidiaries \| Maximum
Debt Instrument
Amount available for issuance under the bank note program			$ 12,000,000,000