STOCK-BASED COMPENSATION.

12 Months Ended

Dec. 31, 2020

Share-based Payment Arrangement [Abstract]

STOCK-BASED COMPENSATION.

SHARES AUTHORIZED FOR STOCK-BASED COMPENSATION PROGRAMS.

At December 31, 2020, a total of 21,858,020 shares of unissued common stock were authorized for issuance under our stock-based compensation plans. Additionally, a total of 1,602,666 shares are authorized for issuance under a plan whereby substantially all employees may acquire common stock through payroll deductions at prevailing market prices.

STOCK OPTIONS.

The following table summarizes the status of, and changes in, our stock options during 2020.


	Options	Weighted- average exercise price		Weighted-average remaining contractual term in years
Outstanding at December 31, 2019	7,388,068	$	71.06

Exercised	(3,046,414)	$	69.01
Forfeited	(6,874)	$	74.48
Expired	(5,724)	$	53.22
Outstanding at December 31, 2020	4,329,056	$	72.52	3.1
Exercisable at December 31, 2020	4,329,056	$	72.52	3.1

Compensation and related costs includes a charge for stock option-based compensation expense of $2.0 million in 2020, $5.1 million in 2019, and $15.3 million in 2018.

The total intrinsic value of options exercised was $198.3 million in 2020, $170.9 million in 2019, and $208.4 million in 2018. At December 31, 2020, the aggregate intrinsic value of in-the-money options outstanding was $341.4 million, all outstanding options are exercisable.

RESTRICTED SHARES AND STOCK UNITS.

The following table summarizes the status of, and changes in, our nonvested restricted shares and restricted stock units during 2020.


	Restricted shares	Restricted stock units	Weighted- average fair value
Nonvested at December 31, 2019	7,404	6,718,261	$	98.75
Time-based grants	7,412	1,780,119	$	151.90
Performance-based grants	—	79,164	$	153.17
Vested (value at vest date was $310.5 million)	(7,404)	(2,096,963)	$	92.14
Nonvested dividend equivalents granted to non-employee directors	—	2,356	$	123.48
Forfeited	—	(115,878)	$	99.76
Nonvested at December 31, 2020	7,412	6,367,059	$	116.51

Nonvested at December 31, 2020 includes performance-based restricted stock units of 416,664. These nonvested performance-based restricted units include 253,260 units for which the performance period has lapsed, and the performance threshold has been met.

Compensation and related costs includes expenses for restricted shares and restricted stock units of $244.1 million in 2020, $201.5 million in 2019, and $181.8 million in 2018.

At December 31, 2020, non-employee directors held 76,352 vested stock units that will convert to common shares upon their separation from the Board.

FUTURE STOCK-BASED COMPENSATION EXPENSE.

The following table presents the compensation expense to be recognized over the remaining vesting periods of the stock-based awards outstanding at December 31, 2020. Estimated future compensation expense will change to reflect future grants, changes in the probability of performance thresholds being met, and adjustments for actual forfeitures.


(in millions)
First quarter 2021	$	58.3
Second quarter 2021	57.0
Third quarter 2021	56.8
Fourth quarter 2021	50.3
Total 2021	222.4
2022 through 2026	215.1
Total	$	437.5