Pension and Other Postretirement Benefit Plans (Textual) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Contribution to corporation's pension plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Contribution to defined benefit pension plan			$ 0.0	$ 0.0
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate			4.15%
Multi-Employer Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Contribution to defined benefit pension plan			$ 0.0
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	$ 1.3	$ 1.0	$ 2.4	$ 1.7