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.

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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.

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Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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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.

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Intangible Assets (Intangible Assets - Additional Information) (Detail) - USD ($) $ in Millions		3 Months Ended
	Mar. 31, 2019	Mar. 31, 2019	Mar. 31, 2018	Mar. 22, 2019
Finite-Lived Intangible Assets
Amortization of Intangible Assets		$ 3	$ 1
Core deposit intangible asset				$ 183
MB Financial, Inc.
Finite-Lived Intangible Assets
Estimated weighted-average life (in years)	6 years 9 months 18 days
Core deposit intangible asset				$ 183