Fair Value Measurements - Aggregate Fair Value, Contractual Balance, and Gain or Loss for Loans Held-For-Sale (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
Sep. 30, 2018	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Aggregate fair value	$ 93,736	$ 52,133
Contractual balance	91,839	50,597
Unrealized gain (loss)	$ 1,897	$ 1,536

Represents the amount of unrealized gain (loss) of loans held for investment.

No definition available.

Name:	chfc_LoansHeldForInvestmentUnrealizedGainLoss
Namespace Prefix:	chfc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration