Annual report pursuant to Section 13 and 15(d)

Earnings Per Share - (Narrative) (Details)

v3.8.0.1
Earnings Per Share - (Narrative) (Details) - shares
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Earnings Per Share [Abstract]      
Antidilutive securities excluded from computation of earnings per share, number of shares 3,009 2,467 3,074