Weighted average amortization period of finite-lived intangible assets acquired either individually or as part of a group of assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
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- Definition

Bank deposits belonging to an acquired bank that can be counted on as a stable source of lending funds. These deposits have the following attributes: predictable costs and low sensitivity to interest rates. This intangible asset is usually amortized over its estimated useful life.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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- Definition

This element represents the identifiable intangible asset established upon acquisition based on a favorable difference between the terms of an acquired lease and the current market terms for that lease at the acquisition date.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
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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.

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Intangible Assets (Intangible Assets - Additional Information) (Detail) - USD ($) $ in Millions		3 Months Ended
	Mar. 22, 2019	Mar. 31, 2020	Mar. 31, 2019
MB Financial, Inc. \| Core deposit intangibles
Finite-Lived Intangible Assets
Core deposit intangible asset	$ 195
Estimated weighted-average life (in years) of acquired intangible asset	7 years 2 months 12 days
MB Financial, Inc. \| Operating lease intangibles
Finite-Lived Intangible Assets
Estimated weighted-average life (in years) of acquired intangible asset	1 year 8 months 12 days
Operating lease intangible asset	$ 24
Intangible asset amortization expense including components of operating lease income [Member]
Finite-Lived Intangible Assets
Amortization of Intangible Assets		$ 16	$ 3