Condensed Consolidated Statements of Stockholders' Equity (Deficit) (Parenthetical) - $ / shares	3 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018
Statement of Stockholders' Equity [Abstract]
Purchase and retirement of common stock (in shares)		16,947,393	8,175,007	8,431,150
Dividends declared on common stock (in dollars per share)	$ 0.10	$ 0.10	$ 0.10	$ 0.10
Issuance of shares of common stock pursuant to employee stock plans (in shares)	1,046,122	552,752	1,286,622	313,744