The time period in which the discount on the acquired loan portfolio is accreted to interest income.

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The fair value discount of the acquired loans at date of acquisition.

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The portion fair value discount of the acquired loans at date of acquisition related to credit assumptions.

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The time period in which the premium on the acquired time deposits is accreted against interest expense.

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The fair value discount of the available for sale securities at date of acquisition.

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The outstanding shares of the acquiree in a business acquisition.

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The fair value premium of the time deposits at the date of acquisition.

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Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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Price of a single share of a number of saleable stocks paid or offered to be paid in a business combination.

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Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

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The amount of financial assets (as defined) recognized as of the acquisition date.

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Amount of intangible assets, excluding goodwill, acquired at the acquisition date.

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The aggregate of all deposit liabilities held by the entity, including foreign and domestic, interest and noninterest bearing; may include demand deposits, saving deposits, Negotiable Order of Withdrawal (NOW) and time deposits among others.

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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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Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

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Net amount of the investment in a contractual right to receive money on demand or on fixed or determinable dates that is recognized as an asset in the creditor's statement of financial position. Examples include, but are not limited to, credit card receivables, notes receivable and receivables relating to lessor's rights to payments from leases other than operating leases that have been recorded as assets. Excludes trade accounts receivable with contractual maturity of one year or less and arose from the sale of goods or services.

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The cash outflow from the repayment of long-term borrowing where a lender is placed in a lien position behind debt having a higher priority of repayment (senior) in case of liquidation of the entity's assets or underlying collateral.

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Amount of time deposit liabilities, including certificates of deposit.

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Any certificate of deposit or savings account held by a bank or other financial institution for a short-term specified period of time. Because of their short-term, time deposits are considered highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three-years ago does not become a cash equivalent when its remaining maturity is three months.

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Basis of Presentation - Recent Acquisitions (Details) - USD ($)			12 Months Ended
	Oct. 01, 2018	Jan. 02, 2018	Dec. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Acquisitions
Goodwill			$ 17,477,000	$ 15,574,000
Total assets			3,884,163,000	6,337,186,000	$ 3,806,949,000
Fair Value of available for sale securities			331,071,000	308,673,000
Deposits			3,231,086,000	5,499,649,000
FMBI \| Stock Purchase Agreement
Acquisitions
Total cost		$ 5,500,000
Goodwill		988,000
Intangible assets		478,000
Time deposits		16,700,000
Time deposits at fair value		16,900,000
Fair value premium of acquired time deposits		$ 185,000
Time deposits, fair value premium, accretion period		20 months
Acquired loan portfolio		$ 27,900,000
Acquired loan portfolio at fair value		27,500,000
Fair value discount on acquired loan portfolio		$ 458,000
FMBI \| Core Deposits \| Stock Purchase Agreement
Acquisitions
Useful life		10 years
FM Bancorp, Inc
Acquisitions
Outstanding shares of the acquiree	27,537
Share price per share	$ 795.29
Total cost	$ 21,900,000
Goodwill	6,900,000
Intangible assets	1,900,000
Fair Value of available for sale securities	66,300,000
Fair value discount on available for sale securities	1,000,000
Time deposits	95,700,000
Time deposits at fair value	95,700,000
Acquired loan portfolio	35,400,000
Acquired loan portfolio at fair value	34,800,000
Fair value discount on acquired loan portfolio	625,000
Discount related to interest assumption	279,000
Discount related to credit assumption	$ 346,000
Acquired loan portfolio, fair value discount, accretion period	72 months
FM Bancorp, Inc \| Core Deposits
Acquisitions
Useful life	10 years
NattyMac, LLC
Acquisitions
Goodwill			3,400,000
Intangible assets			1,600,000
Repayments of subordinated debt			$ 30,000,000
NattyMac, LLC \| Customer Lists
Acquisitions
Useful life			21 months
FMBI
Acquisitions
Total assets			$ 43,000,000
FMBI \| Stock Purchase Agreement
Acquisitions
Acquired loan portfolio, fair value discount, accretion period		39 months
FM Bancorp
Acquisitions
Total assets				110,000,000
Fair Value of available for sale securities				66,300,000
Time deposits				95,700,000
Net loans receivable				$ 35,000,000