Consolidated Statements Of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Amortization of net actuarial loss TAX	$ 0	$ 1	$ 0	$ 1
Amortization of prior service credit TAX	0	0	0	0
Unrealized gain (loss) on investments TAX	0	0	0	1
Reclassification adjustments included in net income TAX	0	0	0	0
Consumers Energy Company
Amortization of net actuarial loss TAX	0	0	0	0
Unrealized gain (loss) on investments TAX	0	0	0	1
Reclassification adjustments included in net income TAX	$ 0	$ 0	$ 0	$ (5)

Amount of tax (expense) benefit of reclassification adjustment from accumulated other comprehensive (income) loss for prior service cost (credit) of defined benefit plan.

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Amount of tax expense (benefit) of reclassification adjustment from accumulated other comprehensive income for unrealized gain (loss) realized upon the sale of available-for-sale securities.

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Amount of tax expense (benefit) of reclassification adjustment from accumulated other comprehensive income (loss) for gain (loss) of defined benefit plan.

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Amount of tax expense (benefit) before reclassification adjustments of unrealized holding gain (loss) on available-for-sale securities.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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