Stock-Based Compensation - Options outstanding (Details) - Stock options shares in Thousands	12 Months Ended
	Dec. 31, 2019 $ / shares shares
Options Outstanding
Number Outstanding (in shares) | shares	9,862
Weighted Average Remaining Contractual Life	3 years 8 months 19 days
Weighted Average Exercise Price (in dollars per share)	$ 53.65
Options Exercisable
Number Exercisable (in shares) | shares	9,862
Weighted Average Exercise Price (in dollars per share)	$ 53.65
$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)	$ 37.41
Options Outstanding
Number Outstanding (in shares) | shares	1,000
Weighted Average Remaining Contractual Life	2 years 7 months 2 days
Weighted Average Exercise Price (in dollars per share)	$ 37.41
Options Exercisable
Number Exercisable (in shares) | shares	1,000
Weighted Average Exercise Price (in dollars per share)	$ 37.41
$54.76-$57.47
Information about options outstanding
Low end of exercise price range (in dollars per share)	54.76
High end of exercise price range (in dollars per share)	$ 57.47
Options Outstanding
Number Outstanding (in shares) | shares	8,862
Weighted Average Remaining Contractual Life	3 years 10 months 6 days
Weighted Average Exercise Price (in dollars per share)	$ 55.48
Options Exercisable
Number Exercisable (in shares) | shares	8,862
Weighted Average Exercise Price (in dollars per share)	$ 55.48