Recent Developments (Details) - Bank Mutual Corporation - USD ($) $ in Millions	Jul. 20, 2017	Jun. 30, 2017
Subsequent Event [Line Items]
Assets acquired		$ 2,700
Deposits acquired		$ 1,900
Subsequent Event
Subsequent Event [Line Items]
Consideration transfered (in shares per share)	0.4220
Transaction value of merger	$ 482

Business Acquisition Assets Reported by Acquired Entity for Last Period

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- Definition

Business Acquisition Deposits Reported by Acquired Entity for Last Period

+ References

No definition available.

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- Definition

Business Combination Consideration Transferred Equity Interests Issued and Issuable Per Share

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- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
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- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

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