Stock compensation plans

We maintain a stock award plan for both employees and non-employee directors. The plan provides for the grant of a variety of equity awards, including options (generally non-qualified options), restricted shares, performance shares, and restricted share units ("RSUs") to key employees (as determined by the Compensation and Management Development Committee of the Board of Directors) for periods not to exceed ten years. Non-employee directors are entitled to an annual distribution of stock options, common shares, or RSUs. All options granted to non-employee directors vest immediately and are exercisable for ten years from the grant date. Options granted to employees generally vest incrementally over four years and are generally exercisable for ten years from the vest date. Restricted shares and RSUs generally cliff vest after three years. Restricted share holders have voting rights during the vesting period and both restricted share and RSU holders receive cash dividends during the vesting period. Performance shares vest upon attainment of the stated performance targets and minimum service requirements and are converted into common shares upon distribution. RSUs represent the right to receive an equal number of common shares and are converted into common shares upon distribution. As of December 31, 2015, there were 25.1 million shares that remained available for grant under the plan.

Our stock compensation expense for the three years ended December 31, 2015, is presented below ($000's omitted):



	2015		2014		2013
Stock options	$	37	$	121	$	1,056
Restricted shares (including RSUs and performance shares)	16,852		13,690		13,418
Long-term incentive plans	7,863		15,481		16,006
	$	24,752	$	29,292	$	30,480

Stock options

A summary of stock option activity for the three years ended December 31, 2015, is presented below (000’s omitted except per share data):



	2015					2014					2013
	Shares			Weighted- Average Per Share Exercise Price		Shares			Weighted- Average Per Share Exercise Price		Shares			Weighted- Average Per Share Exercise Price
Outstanding, beginning of year	9,370			$	23	12,887			$	23	17,148			$	22
Granted	—			—		—			—		—			—
Exercised	(904		)	12		(1,422		)	11		(1,432		)	14
Forfeited	(2,426		)	37		(2,095		)	29		(2,829		)	25
Outstanding, end of year	6,040			$	19	9,370			$	23	12,887			$	23
Options exercisable at year end	6,040			$	19	9,265			$	23	12,402			$	23
Weighted-average per share fair value of options granted during the year	$	—				$	—				$	—

The following table summarizes information about the weighted-average remaining contractual lives of stock options outstanding and exercisable at December 31, 2015:



	Options Outstanding				Options Exercisable
	Number Outstanding (000's omitted)	Weighted- Average Remaining Contract Life (in years)	Weighted- Average Per Share Exercise Price		Number Exercisable (000's omitted)	Weighted- Average Per Share Exercise Price
$0.01 to $10.00	326	4.8	$	8	326	$	8
$10.01 to $20.00	3,697	3.5	12		3,697	12
$20.01 to $30.00	152	1.0	28		152	28
$30.01 to $40.00	1,865	1.0	34		1,865	34
	6,040	2.7	$	19	6,040	$	19

We did not issue any stock options during 2015, 2014, or 2013. As a result, there is no unrecognized compensation cost related to stock option awards at December 31, 2015. The intrinsic value of a stock option is the amount by which the market value of the underlying stock exceeds the exercise price of the option. The aggregate intrinsic value of stock options that were exercised during 2015, 2014, and 2013 was $9.4 million, $14.1 million, and $10.8 million, respectively. As of December 31, 2015, options outstanding had an intrinsic value of $25.3 million, of which $25.3 million related to options exercisable.

Restricted shares (including RSUs and performance shares)

A summary of restricted share activity, including RSUs and performance shares, for the three years ended December 31, 2015, is presented below (000’s omitted, except per share data):



	2015				2014				2013
	Shares		Weighted- Average Per Share Grant Date Fair Value		Shares		Weighted- Average Per Share Grant Date Fair Value		Shares		Weighted- Average Per Share Grant Date Fair Value
Outstanding, beginning of year	2,890		$	15	3,211		$	11	3,822		$	9
Granted	932		$	22	974		$	19	806		$	21
Distributed	(1,090	)	$	10	(1,019	)	$	10	(1,391	)	$	11
Forfeited	(156	)	$	19	(276	)	$	15	(26	)	$	15
Outstanding, end of year	2,576		$	18	2,890		$	15	3,211		$	11
Vested, end of year	89		$	14	75		$	13	60		$	12

During 2015, 2014, and 2013, the total fair value of shares vested during the year was $10.2 million, $8.1 million, and $12.7 million, respectively. Unamortized compensation cost related to restricted share awards was $16.0 million at December 31, 2015. These costs will be expensed over a weighted-average period of approximately 2 years. Additionally, there were 88,727 RSUs outstanding at December 31, 2015, that had vested but had not yet been paid out because the payout date had been deferred by the holder.

Long-term incentive plans

We maintain a long-term incentive plan for certain of our field employees that provides awards based on the achievement of stated performance targets over a three-year period. Awards are earned each year in the form of share units that are paid out in cash at the end of the performance period based upon the number of share units earned times the share price at the end of the performance period. Accordingly, the liability associated with the awards is adjusted each reporting period based on movements in the share price and totaled $2.7 million and $9.5 million at December 31, 2015 and 2014, respectively.

We also maintain a long-term performance award plan for senior management that provides awards based on the achievement of stated performance targets over a three-year period. Awards are earned based on our cumulative performance over the performance period and are stated in dollars but settled in common shares based on the stock price at the end of the performance period. If the share price falls below a floor of $5.00 per share at the end of the performance period or we do not have a sufficient number of shares available under our stock incentive plans at the time of settlement, then a portion of each award will be paid in cash. We recognize expense for these awards based on the probability of achievement of the stated performance targets. The liability for these awards totaled $20.5 million and $26.2 million at December 31, 2015 and 2014, respectively.