Share-Based Compensation (Tables)

12 Months Ended

Mar. 31, 2017

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Total compensation expense related to SARs and RSUs under the long term incentive plans

Total compensation expense related to Hindalco SARs, Novelis SARs, and RSUs under the plans for the respective periods is presented in the table below (in millions). These amounts are included in “Selling, general and administrative expenses” in our consolidated statements of operations. As the performance criteria for fiscal years 2018, 2019 and 2020 have not yet been established, measurement periods for Hindalco SARs and Novelis SARs relating to those periods have not yet commenced. As a result, only compensation expense for vested and current year Hindalco SARs and Novelis SARs has been recorded.

	Year Ended March 31,
	2017		2016			2015
Total compensation expense (income)	$	21	$	(2	)	$	9

RSUs activity and SARs activity under LTIP

The table below shows the RSUs activity for the year ended March 31, 2017.

	Number of RSUs		Grant Date Fair Value (in Indian Rupees)	Aggregate Intrinsic Value (USD in millions)
RSUs outstanding as of March 31, 2016	4,582,725		124.52	$	7
Granted	5,382,251		92.20	—
Exercised	(1,374,877	)	108.37	2
Forfeited/Cancelled	(877,115	)	117.18	—
RSUs outstanding as of March 31, 2017	7,712,984		105.68	$	23

The table below shows Hindalco SARs activity for the year ended March 31, 2017.

	Number of Hindalco SARs		Weighted Average Exercise Price (in Indian Rupees)	Weighted Average Remaining Contractual Term (In years)	Aggregate Intrinsic Value (USD in millions)
SARs outstanding as of March 31, 2016	21,493,712		125.65	4.4	$	—
Granted	3,687,728		92.52	6.1	—
Exercised	(7,175,896	)	118.92	—	7
Forfeited/Cancelled	(2,844,311	)	117.00	—	—
SARs outstanding as of March 31, 2017	15,161,233		122.16	4.4	18
SARs exercisable as of March 31, 2017	4,422,990		139.54	2.8	$	4

The table below shows the Novelis SARs activity for the year ended March 31, 2017.

	Number of Novelis SARs		Weighted Average Exercise Price (in USD)		Weighted Average Remaining Contractual Term (In years)	Aggregate Intrinsic Value (USD in millions)
SARs outstanding as of March 31, 2016	1,341,883		$	80.00	5.1	$	—
Exercised	(12,739	)	64.40		—	—
Forfeited/Cancelled	(1,220,595	)	79.85		—	—
SARs outstanding as of March 31, 2017	108,549		83.57		3.5	—
SARs exercisable as of March 31, 2017	65,185		$	86.89	2.8	$	—

Assumptions used in estimating fair value of each SAR under LTIP

The fair value of each unvested Hindalco SAR was estimated using the following assumptions:

	Year ended March 31,
	2017		2016		2015
Risk-free interest rate	5.82% - 6.99%		7.23% - 7.68%		7.75% - 7.79%
Dividend yield	0.51	%	1.14	%	0.78	%
Volatility	35% - 44%		43% - 44%		39% - 46%

The fair value of each unvested Novelis SAR was estimated using the following assumptions:

	Year ended March 31,
	2017		2016		2015
Risk-free interest rate	0.78% - 1.95%		0.89% - 1.39%		0.96% - 1.59%
Dividend yield	—	%	—	%	—	%
Volatility	25% - 28%		38% - 41%		27% - 34%