Earnings per Share (Details) - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Weighted average common shares outstanding - basic	112,000,000	123,000,000	112,000,000	127,000,000
Dilutive effect of employee stock plans	1,000,000	1,000,000
Shares used for diluted earnings per share	113,000,000	124,000,000	113,000,000	128,000,000
Net income per share - basic	$ 0.29	$ 0.14	$ 0.59	$ 0.34
Net income per share - diluted	$ 0.29	$ 0.14	$ 0.58	$ 0.34