Share-based Compensation and Employee Benefits - Share-based Compensation - Narrative (Details) - Restricted Stock Awards - Class P - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Kinder Morgan, Inc. Amended and Restated Stock Compensation Plan for Non-Employee Directors
Share-based Payment Arrangement, Noncash Expense [Abstract]
Shares of Class P common stock authorized under the plan	250,000
Kinder Morgan, Inc. Amended and Restated Stock Compensation Plan for Non-Employee Directors \| Six Month Vesting Period [Member]
Share-based Payment Arrangement, Noncash Expense [Abstract]
Grants during the period (shares)	23,100	25,800	17,740
Value of shares granted	$ 0.4	$ 0.5	$ 0.4
Award vesting period	6 months
Kinder Morgan Inc 2015 Amended and Restated Stock Incentive Plan
Share-based Payment Arrangement, Noncash Expense [Abstract]
Shares of Class P common stock authorized under the plan	33,000,000
Grants during the period (shares)	3,791,674	5,389,476	3,221,691
Intrinsic value of restricted stock vested	$ 87.0	$ 42.0	$ 30.0
Expense related to restricted stock awards	62.0	63.0	65.0
Amounts capitalized related to restricted stock awards	12.0	$ 13.0	$ 9.0
Unrecognized compensation costs	$ 119.0
Unrecognized compensation costs, weighted average remaining amortization period	2 years 2 months 23 days
Kinder Morgan Inc 2015 Amended and Restated Stock Incentive Plan \| Minimum
Share-based Payment Arrangement, Noncash Expense [Abstract]
Award vesting period	1 year
Kinder Morgan Inc 2015 Amended and Restated Stock Incentive Plan \| Maximum
Share-based Payment Arrangement, Noncash Expense [Abstract]
Award vesting period	10 years

Amount of cost capitalized for award under share-based payment arrangement.

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Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Amount of cost to be recognized for nonvested award under share-based payment arrangement. Excludes share and unit options.

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Amount of noncash expense for award of restricted stock or unit under share-based payment arrangement.

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Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

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Number of shares authorized for issuance under share-based payment arrangement.

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Intrinsic value of vested award under share-based payment arrangement. Excludes share and unit options.

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