Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Preferred stock, par value (in usd per share)	$ 0.01	$ 0.01
Preferred stock, authorized shares	500,000,000	500,000,000
Preferred stock, issued shares	0	0
Preferred stock, outstanding shares	0	0
Common stock, par value (in usd per share)	$ 0.01	$ 0.01
Common stock, authorized shares	5,000,000,000	5,000,000,000
Common stock, issued shares	516,000,000	514,000,000
Common stock, outstanding shares	492,000,000	491,000,000