We have a long-term incentive program whereby eligible employees may be granted restricted stock units, non-qualified stock options and performance stock units. The Executive Compensation Committee of the Board of Directors administers these plans. We settle stock awards with treasury shares. At December 31, 2019, there were 16,668,426 shares available for future grants under our long-term incentive program.

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



	2019				2018
	Shares		Weighted average grant date fair value		Shares		Weighted average grant date fair value
Outstanding - beginning of the year	3,228,339		$	13.33	2,651,053		$	14.16
Granted	3,113,886		6.56		1,754,098		12.36
Vested	(1,360,219	)	11.90		(963,010	)	11.41
Forfeited	(501,159	)	8.71		(213,802	)	13.26
Outstanding - end of the year	4,480,847		$	9.51	3,228,339		$	13.33

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, 2019, there was $13 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, 2019 was $18 million. The intrinsic value of RSUs vested during 2019, 2018 and 2017 was $16 million, $17 million and $26 million, respectively. The fair value of RSUs vested during 2019, 2018 and 2017 was $18 million, $18 million and $14 million, respectively. During 2017, we granted 1,995,473 RSUs at a weighted average fair value of $13.24.

In 2019 and 2018, we granted 155,709 and 131,420 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 as well as 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. However, the final determination of the number of shares to be issued is made by our 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.



	2019				2018
	Shares		Weighted average grant date fair value		Shares		Weighted average grant date fair value
Outstanding - beginning of the year	1,653,004		$	13.08	1,145,025		$	13.43
Granted	1,368,182		6.60		733,148		12.64
Vested	—		—		(91,493	)	12.21
Forfeited	(242,824	)	9.65		(133,676	)	14.26
Outstanding - end of the year	2,778,362		$	10.09	1,653,004		$	13.08

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.

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, 2019, there was $3 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 and options exercisable at December 31, 2019 was not significant. There were no stock option exercises in 2019, 2018 or 2017.



	2019				2018
	Shares		Per share weighted average exercise prices		Shares		Per share weighted average exercise prices
Options outstanding - beginning of the year	13,593,156		$	15.30	10,495,039		$	21.67
Granted	869,297		6.57		4,932,467		8.47
Canceled	(533,921	)	11.06		(258,509	)	13.09
Expired	(1,105,848	)	24.75		(1,575,841	)	36.86
Options outstanding - end of the year	12,822,684		$	14.08	13,593,156		$	15.30
Options exercisable - end of the year	7,288,614		$	18.49	6,824,433		$	20.23



	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
$4.32 - $8.55	3,855,770	$	6.18	9.0	years	—	$	—	—
$12.64 - $19.45	6,001,756	14.36		6.6	years	4,323,456	14.86		6.2	years
$21.54 - $26.07	2,965,158	23.77		1.6	years	2,965,158	23.77		1.6	years
	12,822,684	$	14.08	6.2	years	7,288,614	$	18.49	4.3	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.

The following table lists the weighted average of assumptions used to calculate the fair value of stock options granted:



	Years Ended December 31,
	2019		2018		2017
Expected dividend yield	3.0	%	9.9	%	5.7	%
Expected stock price volatility	41.5	%	37.8	%	29.7	%
Risk-free interest rate	2.5	%	2.8	%	2.3	%
Expected life	5 years		7 years		7 years
Weighted-average fair value per option granted	$1.98		$1.26		$2.00
Fair value of options granted	$1,722		$6,229		$5,107