Income Taxes (Policy)

12 Months Ended

Dec. 31, 2011

Income Tax Policy

CMS Energy and its subsidiaries file a consolidated U.S. federal income tax return and a unitary Michigan income tax return. Income taxes are allocated based on each company's separate taxable income in accordance with the CMS Energy tax sharing agreement.

Consumers Energy Company [Member]

Income Tax Policy

CMS Energy and its subsidiaries file a consolidated U.S. federal income tax return and a unitary Michigan income tax return. Income taxes are allocated based on each company's separate taxable income in accordance with the CMS Energy tax sharing agreement.