Condensed Consolidated Balance Sheets (Parenthetical) - Unaudited - $ / shares	Jun. 30, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	160,000,000	120,000,000
Common stock, shares issued	116,461,171	108,513,597
Common stock, shares outstanding	116,357,739	108,510,160
Treasury stock, shares	103,432	3,437