CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Mar. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	50,000,000	50,000,000
Preferred stock, shares issued	4,475,000	4,475,000
Preferred stock, shares outstanding	4,475,000	4,475,000
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	1,000,000,000	1,000,000,000
Common stock, shares issued	658,714,887	653,736,607
Common stock, shares outstanding	482,765,459	480,218,547
Treasury stock, common, shares	175,949,428	173,518,060