CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2017	Dec. 31, 2016
CONSOLIDATED BALANCE SHEETS
Preferred stock and paid in capital, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock and paid in capital, shares authorized	69,900,000	69,900,000
Preferred stock and paid in capital, shares issued	0	16,350,000
Preferred stock and paid in capital, shares outstanding	0	16,350,000
Preferred stock liquidation preference (in dollars per share)		$ 25.00
Common stock and paid in capital, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock and paid in capital, shares authorized	370,100,000	370,100,000
Common stock and paid in capital, shares issued	284,213,685	260,168,259
Common stock and paid in capital, shares outstanding	284,213,685	260,168,259