Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2017

Schedule Of Restricted Stock Activity

	CMS Energy, including Consumers				Consumers
Year Ended December 31, 2017	Number of  Shares	Weighted-Average  Grant Date Fair Value  per Share			Number of  Shares	Weighted-Average  Grant Date Fair Value  per Share
Nonvested at beginning of period	1,387,597		$	32.44	1,328,631		$	32.41
Granted
Restricted stock	722,215			28.61	691,052			28.67
Restricted stock units	12,388			41.98	11,970			41.97
Vested
Restricted stock	(819,795)			19.53	(787,039)			19.56
Restricted stock units	(15,638)			38.37	(15,199)			38.37
Forfeited – restricted stock	(93,501)			39.19	(84,293)			39.19
Nonvested at end of period	1,193,266		$	38.48	1,145,122		$	38.50

Year Ended December 31, 2017	CMS Energy, including  Consumers	Consumers
Granted
Time-lapse awards	164,640	159,260
Market-based awards	157,064	149,870
Performance-based awards	157,064	149,870
Restricted stock units	11,444	11,055
Dividends on market-based awards	24,137	22,976
Dividends on performance-based awards	22,894	21,791
Dividends on restricted stock units	944	915
Additional market-based shares based on achievement of condition	113,079	107,823
Additional performance-based shares based on achievement of condition	83,337	79,462
Total granted	734,603	703,022

Schedule of Share-based Payment Award, Restricted Stock, Valuation Assumptions

Years Ended December 31	2017			2016			2015
Expected volatility		18.0	%		16.7	%		14.1	%
Expected dividend yield		3.0			3.2			3.3
Risk-free rate		1.5			1.0			0.8

Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value

Years Ended December 31	2017			2016			2015
CMS Energy, including Consumers
Weighted-average grant-date fair value per share
Restricted stock granted		$	28.61		$	31.74		$	36.84
Restricted stock units granted			41.98			39.12			34.25
Consumers
Weighted-average grant-date fair value per share
Restricted stock granted		$	28.67		$	31.77		$	36.83
Restricted stock units granted			41.97			39.12			34.25

Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs by Plan

In Millions
Years Ended December 31	2017			2016			2015
CMS Energy, including Consumers
Fair value of shares that vested during the year		$	37		$	31		$	29
Compensation expense recognized			17			16			20
Income tax benefit recognized			7			7			8
Consumers
Fair value of shares that vested during the year		$	35		$	30		$	28
Compensation expense recognized			16			16			19
Income tax benefit recognized			7			6			7

Consumers Energy Company [Member]

Schedule Of Restricted Stock Activity

	CMS Energy, including Consumers				Consumers
Year Ended December 31, 2017	Number of  Shares	Weighted-Average  Grant Date Fair Value  per Share			Number of  Shares	Weighted-Average  Grant Date Fair Value  per Share
Nonvested at beginning of period	1,387,597		$	32.44	1,328,631		$	32.41
Granted
Restricted stock	722,215			28.61	691,052			28.67
Restricted stock units	12,388			41.98	11,970			41.97
Vested
Restricted stock	(819,795)			19.53	(787,039)			19.56
Restricted stock units	(15,638)			38.37	(15,199)			38.37
Forfeited – restricted stock	(93,501)			39.19	(84,293)			39.19
Nonvested at end of period	1,193,266		$	38.48	1,145,122		$	38.50

Year Ended December 31, 2017	CMS Energy, including  Consumers	Consumers
Granted
Time-lapse awards	164,640	159,260
Market-based awards	157,064	149,870
Performance-based awards	157,064	149,870
Restricted stock units	11,444	11,055
Dividends on market-based awards	24,137	22,976
Dividends on performance-based awards	22,894	21,791
Dividends on restricted stock units	944	915
Additional market-based shares based on achievement of condition	113,079	107,823
Additional performance-based shares based on achievement of condition	83,337	79,462
Total granted	734,603	703,022

Schedule of Share-based Payment Award, Restricted Stock, Valuation Assumptions

Years Ended December 31	2017			2016			2015
Expected volatility		18.0	%		16.7	%		14.1	%
Expected dividend yield		3.0			3.2			3.3
Risk-free rate		1.5			1.0			0.8

Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value

Years Ended December 31	2017			2016			2015
CMS Energy, including Consumers
Weighted-average grant-date fair value per share
Restricted stock granted		$	28.61		$	31.74		$	36.84
Restricted stock units granted			41.98			39.12			34.25
Consumers
Weighted-average grant-date fair value per share
Restricted stock granted		$	28.67		$	31.77		$	36.83
Restricted stock units granted			41.97			39.12			34.25

Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs by Plan

In Millions
Years Ended December 31	2017			2016			2015
CMS Energy, including Consumers
Fair value of shares that vested during the year		$	37		$	31		$	29
Compensation expense recognized			17			16			20
Income tax benefit recognized			7			7			8
Consumers
Fair value of shares that vested during the year		$	35		$	30		$	28
Compensation expense recognized			16			16			19
Income tax benefit recognized			7			6			7