Pension and Other Postretirement Benefit Plans (Textual) (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended	12 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Mar. 31, 2015	Jun. 30, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Multiemployer Plan, Period Contributions				$ 0.0
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Contribution to defined benefit pension plan				$ 0.0	$ 0.0
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate				4.55%
Chemical Financial Corporation [Member]
Defined Benefit Plan Disclosure [Line Items]
Percentage of eligible pay contribution to certain employees				4.00%
Defined Contribution Plan, Employer Total Contribution Amount	$ 1.4	$ 1.3	$ 2.4	$ 2.7