STOCK-BASED COMPENSATION. (Tables)

3 Months Ended

Mar. 31, 2020

Share-based Payment Arrangement [Abstract]

Rollforward of stock options

The following table summarizes the status of, and changes in, our stock options during the three months ended March 31, 2020.

	Options		Weighted- average exercise price
Outstanding at December 31, 2019	7,388,068		$	71.06
Exercised	(1,540,694	)	$	67.50
Forfeited	(1,428	)	$	76.00
Outstanding at March 31, 2020	5,845,946		$	72.00
Exercisable at March 31, 2020	5,176,419		$	71.50

Rollforward of nonvested restricted shares and restricted stock units

The following table summarizes the status of, and changes in, our nonvested restricted shares and restricted stock units during the three months ended March 31, 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	—	15,184		$	126.33
Dividend equivalents granted to non-employee directors	—	643		$	98.80
Vested	—	(62,499	)	$	95.26
Forfeited	—	(34,004	)	$	97.30
Nonvested at March 31, 2020	7,404	6,637,585		$	98.85

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 March 31, 2020. Estimated future compensation expense will change to reflect future grants of restricted stock awards and units, future option grants, changes in the probability of performance thresholds being met, and adjustments for actual forfeitures.

(in millions)
Second quarter 2020	$	54.5
Third quarter 2020	53.2
Fourth quarter 2020	46.2
2021	108.1
2022 through 2026	90.0
Total	$	352.0