Summary of Significant Accounting Policies (Income Taxes and Investment in Tax Credit Projects) (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Accounting Policies [Abstract]
Contingent income tax liabilities recorded	$ 0	$ 0

Reserve for contingent income tax liabilities recorded.

No definition available.

Name:	chfc_ReserveForContingentIncomeTaxLiabilitiesRecorded
Namespace Prefix:	chfc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant