Regulatory Capital (Tables)

3 Months Ended

Mar. 31, 2013

Banking and Thrift [Abstract]

Corporation's and Chemical Bank's actual capital amounts and ratios with the quantitative measures established by regulation to ensure capital adequacy

The summary below compares the Corporation’s and Chemical Bank’s actual capital amounts and ratios with the quantitative measures established by regulation to ensure capital adequacy:

	Actual				Minimum Required for Capital Adequacy Purposes				Required to be Well Capitalized Under Prompt Corrective Action Regulations
	Capital Amount		Ratio		Capital Amount		Ratio		Capital Amount		Ratio
	(Dollars in thousands)
March 31, 2013
Total Capital to Risk-Weighted Assets:
Corporation	$	561,092	13.3	%	$	337,508	8.0	%	N/A		N/A
Chemical Bank	545,361		13.0		336,576		8.0		$	420,720	10.0	%
Tier 1 Capital to Risk-Weighted Assets:
Corporation	507,985		12.0		168,754		4.0		N/A		N/A
Chemical Bank	492,398		11.7		168,288		4.0		252,432		6.0
Leverage Ratio:
Corporation	507,985		8.8		230,992		4.0		N/A		N/A
Chemical Bank	492,398		8.5		230,544		4.0		288,179		5.0
December 31, 2012
Total Capital to Risk-Weighted Assets:
Corporation	$	552,171	13.2	%	$	334,140	8.0	%	N/A		N/A
Chemical Bank	536,223		12.9		333,195		8.0		$	416,494	10.0	%
Tier 1 Capital to Risk-Weighted Assets:
Corporation	499,563		12.0		167,070		4.0		N/A		N/A
Chemical Bank	483,761		11.6		166,598		4.0		249,896		6.0
Leverage Ratio:
Corporation	499,563		9.2		217,145		4.0		N/A		N/A
Chemical Bank	483,761		8.9		216,784		4.0		270,980		5.0
March 31, 2012
Total Capital to Risk-Weighted Assets:
Corporation	$	528,910	13.7	%	$	309,209	8.0	%	N/A		N/A
Chemical Bank	522,775		13.5		309,024		8.0		$	386,280	10.0	%
Tier 1 Capital to Risk-Weighted Assets:
Corporation	480,109		12.4		154,605		4.0		N/A		N/A
Chemical Bank	474,002		12.3		154,512		4.0		231,768		6.0
Leverage Ratio:
Corporation	481,109		9.1		210,126		4.0		N/A		N/A
Chemical Bank	474,002		9.0		210,055		4.0		262,569		5.0