Annual report pursuant to Section 13 and 15(d)

Earnings per Share - Additional Information (Details)

v3.8.0.1
Earnings per Share - Additional Information (Details) - shares
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Earnings Per Share [Abstract]      
Participating securities (in shares) 0 0 0
Anti-dilutive common stock equivalents (in shares) 40,541,000 208,202,000 151,112,000