Long-Term Debt (Tables)

12 Months Ended

Dec. 31, 2017

Debt Disclosure [Abstract]

Summary of Long-Term Debt

Long-term debt consists of borrowings having an original maturity of one year or more. The following is a summary of the Company's long-term debt:

(Dollars in millions)	December 31, 2017		December 31, 2016
Debt issued by MUAH
Senior debt:
Floating rate senior notes due February 2018. These notes, which bear interest at 0.57% above 3-month LIBOR, had a rate of 1.97% at December 31, 2017 and 1.46% at December 31, 2016	$	250	$	250
Fixed rate 1.625% notes due February 2018	450		449
Fixed rate 2.25% notes due February 2020	998		997
Fixed rate 3.50% notes due June 2022	398		397
Fixed rate 3.00% notes due February 2025	496		496
Senior debt due to BTMU:
Floating rate debt due March 2020. This note, which bears interest at 0.86% above 3-month LIBOR, had a rate of 2.45% at December 31, 2017 and 1.82% at December 31, 2016	545		545
Floating rate debt due September 2020. This note, which bears interest at 0.85% above 3-month LIBOR, had a rate of 2.54% at December 31, 2017	3,500		—
Floating rate debt due December 2023. This note, which bears interest at 0.76% above 3-month EURIBOR, had a rate of 0.76% at December 31, 2017	24		—
Subordinated debt due to BTMU:
Floating rate subordinated debt due December 2023. This note, which bears interest at 1.38% above 3-month LIBOR, had a rate of 3.07% at December 31, 2017 and 2.38% at December 31, 2016	300		300
Junior subordinated debt payable to trusts:
Floating rate note due September 2036. This note had an interest rate of 3.29% at December 31, 2017 and 2.66% at December 31, 2016	36		36
Total debt issued by MUAH	6,997		3,470
Debt issued by MUB
Senior debt:
Floating rate notes due May 2017. These notes, which bear interest at 0.40% above 3-month LIBOR, had a rate of 1.28% at December 31, 2016	—		250
Fixed rate 2.125% notes due June 2017	—		500
Fixed rate FHLB of San Francisco advances due between May 2018 and January 2019. These notes bear a combined weighted-average rate of 1.51% at December 31, 2017	1,500		—
Fixed rate 2.625% notes due September 2018	1,000		999
Fixed rate 2.250% notes due May 2019	497		500
Senior debt due to BTMU:
Floating rate debt due January 2018. This note, which bears interest at 0.85% above 1-month LIBOR, had a rate of 1.47% at December 31, 2016	—		1,000
Floating rate debt due January 2018. This note, which bears interest at 0.87% above 1-month LIBOR, had a rate of 1.49% at December 31, 2016	—		1,500
Floating rate debt due January 2018. This note, which bears interest at 1.03% above 1-month LIBOR, had a rate of 1.65% at December 31, 2016	—		1,000
Subordinated debt due to BTMU:
Floating rate subordinated debt due June 2023. This note, which bears interest at 1.20% above 3-month LIBOR, had a rate of 2.89% at December 31, 2017 and 2.20% at December 31, 2016	750		750
Other	63		58
Total debt issued by MUB	3,810		6,557

Debt issued by other MUAH subsidiaries
Senior debt due to BTMU:
Various floating rate borrowings due between July 2019 and May 2021. These notes, which bear interest above 3-month LIBOR had a weighted-average interest rate of 1.78% at December 31, 2017 and 0.99% at December 31, 2016	291		250
Various fixed rate borrowings due between March 2018 and December 2024 with a weighted-average interest rate of 2.12% (between 1.37% and 2.65%) at December 31, 2017 and 2.15% (between 1.71% and 2.44%) at December 31, 2016	339		384
Subordinated debt due to Affiliate:
Various floating rate borrowings due between March 2018 and March 2019. These notes, which bear interest above 6-month LIBOR had a weighted-average interest rate of 2.95% (between 2.88% and 3.04%) at December 31, 2017 and 2.68% (between 2.61% and 2.77%) at December 31, 2016	185		185
Non-recourse debt due to BTMU:
Various floating rate non-recourse borrowings due to BTMU between June 2018 and December 2021. These notes, which bear interest above 1- or 3-month LIBOR had a weighted-average interest rate of 3.07% (between 1.49% and 5.58%) at December 31, 2017 and 1.67% (between 0.25% and 2.41%) at December 31, 2016	79		127
Fixed rate non-recourse borrowings due to BTMU between January 2019 and March 2023 which had an interest rate of 3.27% at December 31, 2017	240		—
Non-recourse debt:
Various floating rate non-recourse borrowings due between December 2018 and May 2019. These notes, which bear interest above 1- or 3-month LIBOR had a weighted-average interest rate of 2.88% (between 2.50% and 3.54%) at December 31, 2017 and 2.04% (between 0.85% and 2.73%) at December 31, 2016	185		398
Fixed rate non-recourse borrowings due December 2026 which had an interest rate of 5.34% at December 31, 2017 and December 31, 2016	36		39
Total debt issued by other MUAH subsidiaries	1,355		1,383
Total long-term debt	$	12,162	$	11,410