Stock-Based Compensation - Options outstanding (Details) - Stock options shares in Thousands	12 Months Ended
	Dec. 31, 2020 $ / shares shares
Options Outstanding
Number Outstanding (in shares) | shares	5
Weighted Average Remaining Contractual Life	2 years 9 months 3 days
Weighted Average Exercise Price (in dollars per share)	$ 52.40
Options Exercisable
Number Exercisable (in shares) | shares	5
Weighted Average Exercise Price (in dollars per share)	$ 52.40
$37.41-$37.41
Information about options outstanding
Low end of exercise price range (in dollars per share)	37.41
High end of exercise price range (in dollars per share)	$ 54.76
Options Outstanding
Number Outstanding (in shares) | shares	3
Weighted Average Remaining Contractual Life	2 years 3 months 14 days
Weighted Average Exercise Price (in dollars per share)	$ 49.53
Options Exercisable
Number Exercisable (in shares) | shares	3
Weighted Average Exercise Price (in dollars per share)	$ 49.53
$57.47-$57.47
Information about options outstanding
Low end of exercise price range (in dollars per share)	57.47
High end of exercise price range (in dollars per share)	$ 57.47
Options Outstanding
Number Outstanding (in shares) | shares	2
Weighted Average Remaining Contractual Life	3 years 6 months 29 days
Weighted Average Exercise Price (in dollars per share)	$ 57.47
Options Exercisable
Number Exercisable (in shares) | shares	2
Weighted Average Exercise Price (in dollars per share)	$ 57.47