Regulatory Capital (Tables)

6 Months Ended

Jun. 30, 2012

Regulatory Capital [Abstract]

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
	(In thousands)
June 30, 2012
Total Capital to Risk-Weighted Assets:
Corporation	$	542,827		13.6	%	$	319,863		8.0	%		N/A		N/A
Chemical Bank		535,868		13.4			319,236		8.0		$	399,045		10.0	%
Tier 1 Capital to Risk-Weighted Assets:
Corporation		492,395		12.3			159,931		4.0			N/A		N/A
Chemical Bank		485,533		12.2			159,618		4.0			239,427		6.0
Leverage Ratio:
Corporation		492,395		9.4			208,808		4.0			N/A		N/A
Chemical Bank		485,533		9.3			208,778		4.0			260,973		5.0
December 31, 2011
Total Capital to Risk-Weighted Assets:
Corporation	$	517,547		13.3	%	$	310,316		8.0	%		N/A		N/A
Chemical Bank		510,290		13.2			310,119		8.0		$	387,649		10.0	%
Tier 1 Capital to Risk-Weighted Assets:
Corporation		468,565		12.1			155,158		4.0			N/A		N/A
Chemical Bank		461,338		11.9			155,060		4.0			232,589		6.0
Leverage Ratio:
Corporation		468,565		9.0			208,013		4.0			N/A		N/A
Chemical Bank		461,338		8.9			208,033		4.0			260,042		5.0
June 30, 2011
Total Capital to Risk-Weighted Assets:
Corporation	$	486,917		13.0	%	$	300,744		8.0	%		N/A		N/A
Chemical Bank		478,734		12.7			300,517		8.0		$	375,646		10.0	%
Tier 1 Capital to Risk-Weighted Assets:
Corporation		439,394		11.7			150,372		4.0			N/A		N/A
Chemical Bank		431,247		11.5			150,258		4.0			225,388		6.0
Leverage Ratio:
Corporation		439,394		8.6			203,915		4.0			N/A		N/A
Chemical Bank		431,247		8.5			203,878		4.0			254,847		5.0