Goodwill (Details) - USD ($)	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Aug. 31, 2016
Goodwill [Line Items]
Goodwill	$ 1,134,568,000	$ 1,134,568,000
Goodwill, Impairment Loss	0	$ 0
Talmer
Goodwill [Line Items]
Goodwill			$ 847,701,000
Goodwill acquired during period	$ 847,700,000

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 of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

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Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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