Name:	cms_AvailableForSaleSecuritiesGrossUnrealizedGainAccumulatedInInvestments
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Amount of accumulated pre-tax unrealized loss before deducting pre-tax unrealized gain on investments in available-for-sale securities impacting investments.

No definition available.

Name:	cms_AvailableForSaleSecuritiesGrossUnrealizedLossAccumulatedInInvestments
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This item represents the excess of amortized cost basis over fair value of securities in a gain position and which are categorized as held-to-maturity.

No definition available.

Name:	cms_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain
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This item represents the excess of amortized cost basis over fair value of securities in a loss position and which are categorized as held-to-maturity.

No definition available.

Name:	cms_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss
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This item represents the cost of equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments for other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

No definition available.

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Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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Amount after other than temporary impairment (OTTI) accretion, of investments in debt securities classified as held-to-maturity.

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Fair value of investments in debt securities classified as held-to-maturity.