We may grant restricted stock units, non-qualified stock options and performance stock units to eligible employees. All stock-based awards are approved by the Executive Compensation Committee of the Board of Directors. We settle stock awards with treasury shares. At December 31, 2021, there were 119,940,056 shares available for future grants.

Restricted stock units (RSUs) typically vest ratably over a three-year service period and entitle the holder to shares of common stock as the units vest. The following table summarizes information about RSUs:


	2021			2020
	Shares	Weighted average fair value		Shares	Weighted average fair value
Outstanding - beginning of the year	6,560,372	$	6.27	4,480,847	$	9.51
Granted	2,100,126	8.36		4,123,544	3.92
Vested	(2,504,189)	6.72		(1,486,371)	9.65
Forfeited	(418,016)	6.61		(557,648)	5.06
Outstanding - end of the year	5,738,293	$	6.95	6,560,372	$	6.27

The fair value of RSUs is determined based on the stock price on the grant date less the present value of expected dividends. At December 31, 2021, there was $9 million of unrecognized compensation cost related to RSUs that is expected to be recognized over a weighted-average period of 1.6 years. The intrinsic value of RSUs outstanding at December 31, 2021 was $38 million. The fair value of RSUs vested during 2021, 2020 and 2019 was $22 million, $6 million and $8 million, respectively. During 2019, we granted 3,113,886 RSUs at a weighted average fair value of $6.56.

In 2021 and 2020, we granted 121,455 and 282,131 RSUs, respectively, to non-employee directors. These RSUs vest one year from the grant date.

Performance stock units (PSUs) are stock awards where the number of shares ultimately received by the employee is conditional upon the attainment of certain performance targets and total shareholder return relative to peer companies. PSUs vest at the end of a three-year service period and the actual number of shares awarded may range from 0% to 200% of the target award. The final determination of the number of shares to be issued is made by the Board of Directors, who may reduce, but not increase, the number of shares to be awarded (negative discretion). PSUs are accounted for as variable awards until the end of the service period when the grant date is established.


	2021			2020
	Shares	Weighted average fair value		Shares	Weighted average fair value
Outstanding - beginning of the year	1,730,002	$	9.31	2,778,362	$	10.09

Vested	(287,109)	9.33		(303,460)	4.00
Forfeited	(433,802)	9.33		(744,900)	11.57

Outstanding - end of the year	1,009,091	$	6.60	1,730,002	$	9.31

Share-based compensation expense for PSUs is recognized ratably over the service period based on the number shares expected to be awarded and the fair value of an award. The fair value of PSUs is determined using a Monte Carlo simulation model. Due to the variability of these awards, significant fluctuations in share-based compensation expense for PSUs recognized from one period to the next are possible. During 2019, we granted 1,368,182 PSUs at an initial award date fair value of $6.60.

Stock options are granted at an exercise price equal to or greater than the stock price of our common stock on the grant date. Options vest ratably over three years and expire ten years from the grant date. At December 31, 2021, there was $2 million of unrecognized compensation cost related to stock options that is expected to be recognized over a weighted-average period of 1.4 years. The intrinsic value of options outstanding at December 31, 2021 was $7 million and the intrinsic value of options exercisable was not significant.


	2021			2020
	Shares	Per share weighted average exercise prices		Shares	Per share weighted average exercise prices
Options outstanding - beginning of the year	12,814,365	$	11.81	12,822,684	$	14.08
Granted	737,842	8.48		2,801,982	3.98
Exercised	(777,429)	6.11		(33,501)	6.82
Canceled	(604,101)	11.71		(1,653,126)	10.09
Expired	(1,050,608)	25.85		(1,123,674)	22.09
Options outstanding - end of the year	11,120,069	$	10.65	12,814,365	$	11.81
Options exercisable - end of the year	8,853,859	$	11.94	7,027,974	$	16.76


	Options Outstanding				Options Exercisable
Range of per share exercise prices	Shares	Per share weighted-average exercise price		Weighted-average remaining contractual life	Shares	Per share weighted-average exercise price		Weighted-average remaining contractual life
$3.98 - $8.76	5,460,787	$	5.65	7.7 years	3,194,577	$	5.69	7.2 years
$12.64 - $16.88	4,857,128	$	14.40	4.5 years	4,857,128	$	14.40	4.5 years
$17.20 - $23.94	802,154	$	21.93	1.2 years	802,154	$	21.93	1.2 years

	11,120,069	$	10.64	5.8 years	8,853,859	$	11.94	5.2 years

The fair value of stock options is determined using a Black-Scholes valuation model and requires assumptions be made regarding the expected stock price volatility, risk-free interest rate, life of the award and dividend yield. The expected stock price volatility is based on historical price changes of our stock. The risk-free interest rate is based on U.S. Treasuries with a term equal to the expected life of the award. The expected life of the award and expected dividend yield are based on historical experience.


	Years Ended December 31,
	2021		2020		2019
Expected dividend yield	2.4	%	5.0	%	3.0	%
Expected stock price volatility	70.0	%	43.0	%	41.5	%
Risk-free interest rate	1.1	%	1.5	%	2.5	%
Expected life	7 years		7 years		5 years
Weighted-average fair value per option granted	$4.53		$1.01		$1.98
Fair value of options granted	$3,342		$2,830		$1,722