Regulatory Capital and Reserve Requirements (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Minimum average regulatory cash reserve balance	$ 29,300,000	$ 27,900,000
Chemical Financial Corporation [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Cash dividends paid to parent company	(24,488,000)	(27,550,000)	(22,000,000)
Risk weighted assets	4,640,000,000	4,180,000,000
Total Capital to Risk-Weighted Assets:
Actual, Capital Amount	649,836,000	552,171,000
Minimum Required for Capital Adequacy Purposes, Capital Amount	371,465,000	334,140,000
Actual, Ratio	14.00%	13.20%
Minimum Required for Capital Adequacy Purposes, Ratio	8.00%	8.00%
Tier 1 Capital to Risk-Weighted Assets:
Actual, Capital Amount	591,535,000	499,563,000
Minimum Required for Capital Adequacy Purposes, Capital Amount	185,732,000	167,070,000
Actual, Ratio	12.70%	12.00%
Minimum Required for Capital Adequacy Purposes, Ratio	4.00%	4.00%
Leverage Ratio:
Actual, Capital Amount	591,535,000	499,563,000
Minimum Required for Capital Adequacy Purposes, Capital Amount	239,010,000	217,145,000
Actual, Ratio	9.90%	9.20%
Minimum Required for Capital Adequacy Purposes, Ratio	4.00%	4.00%
Chemical Bank [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Cash dividends paid to parent company	24,488,000	27,550,000	22,000,000
Risk weighted assets	4,640,000,000	4,160,000,000
Total Capital to Risk-Weighted Assets:
Actual, Capital Amount	579,494,000	536,223,000
Minimum Required for Capital Adequacy Purposes, Capital Amount	370,881,000	333,195,000
Required to be Well Capitalized Under Prompt Corrective Action Regulations, Capital Amount	463,601,000	416,494,000
Actual, Ratio	12.50%	12.90%
Minimum Required for Capital Adequacy Purposes, Ratio	8.00%	8.00%
Required to be Well Capitalized Under Prompt Corrective Action Regulations, Ratio	10.00%	10.00%
Tier 1 Capital to Risk-Weighted Assets:
Actual, Capital Amount	521,283,000	483,761,000
Minimum Required for Capital Adequacy Purposes, Capital Amount	185,440,000	166,598,000
Required to be Well Capitalized Under Prompt Corrective Action Regulations, Capital Amount	278,160,000	249,896,000
Actual, Ratio	11.20%	11.60%
Minimum Required for Capital Adequacy Purposes, Ratio	4.00%	4.00%
Required to be Well Capitalized Under Prompt Corrective Action Regulations, Ratio	6.00%	6.00%
Leverage Ratio:
Actual, Capital Amount	521,283,000	483,761,000
Minimum Required for Capital Adequacy Purposes, Capital Amount	238,884,000	216,784,000
Required to be Well Capitalized Under Prompt Corrective Action Regulations, Capital Amount	$ 298,605,000	$ 270,980,000
Actual, Ratio	8.70%	8.90%
Minimum Required for Capital Adequacy Purposes, Ratio	4.00%	4.00%
Required to be Well Capitalized Under Prompt Corrective Action Regulations, Ratio	5.00%	5.00%