Equity - Narrative (Details) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Class Of Stock [Line Items]
Common stock, shares authorized (in shares)	75,000,000	75,000,000
Par value of common stock (in dollars per share)	$ 0.01
Preferred stock, shares authorized (in shares)	3,500,000	3,500,000
Par value of preferred stock per share (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares issued (in shares)	0
Dividends per common share (in dollars per share)	$ 0	$ 0	$ 0.08
Maximum
Class Of Stock [Line Items]
Number of shares authorized to be repurchased (in shares)	600,000