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Interest rate on the amount to be repaid to the counterparty to the sweep product repurchase agreement when the carrying amount (or market value, if higher than the carrying amount) of securities or other assets sold under the repurchase agreement exceeds 10 percent of total assets.

No definition available.

Name:	colb_AssetsSoldunderAgreementstoRepurchaseSweepInterestrate
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Carrying amount of assets sold under term agreements to repurchase when the carrying amount (or market value, if higher than the carrying amount) of securities or other assets sold under repurchase agreements exceeds 10 percent of total assets.

No definition available.

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Interest rate on the amount to be repaid to the counterparty to the Term repurchase agreement when the carrying amount (or market value, if higher than the carrying amount) of securities or other assets sold under the repurchase agreement exceeds 10 percent of total assets.

No definition available.

Name:	colb_AssetsSoldunderAgreementstoRepurchaseTermInterestrate
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The fair value of available-for-sale securities that serve as collateral for borrowings.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=35738203&loc=d3e5086-111524

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