Earnings per Share (Details) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Weighted average common shares outstanding - basic	112,000,000	121,000,000	112,000,000	125,000,000
Dilutive effect of employee stock plans	1,000,000	1,000,000	1,000,000
Shares used for diluted earnings per share	113,000,000	122,000,000	113,000,000	126,000,000
Net income per share - basic	$ 1.58	$ 0.02	$ 2.16	$ 0.37
Net income per share - diluted	$ 1.57	$ 0.02	$ 2.15	$ 0.36