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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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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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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This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities.

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In a business combination in which the amount of net identifiable assets acquired and liabilities assumed exceeds the aggregate consideration transferred or to be transferred (as defined), this element represents the amount of gain recognized by the entity.

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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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Fair value at acquisition of acquired loans accounted for as debt securities with evidence of deterioration of credit quality.

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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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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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Business Combinations (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended
	May 01, 2018	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017	Jan. 13, 2017	Mar. 11, 2016
Business Acquisition [Line Items]
Assets		$ 34,436,437		$ 34,527,512
Loans and Leases		23,611,977		23,596,825
Deposits		29,969,245		29,266,275
PCI loans and leases					$ 0	$ 85,149
Gain on acquisitions		0	$ 12,017
Merger-related expenses		598	$ 833
Goodwill		150,601		$ 150,601
HomeBancorp Inc. [Member]
Business Acquisition [Line Items]
Assets		912,600
Loans and Leases		597,700
Deposits		$ 647,100
Subsequent Event [Member] \| HomeBancorp Inc. [Member]
Business Acquisition [Line Items]
Business Acquisition, Share Price	$ 15.03
Business Combination, Consideration Transferred	$ 113,700