Annual report pursuant to Section 13 and 15(d)

Earnings per Share (Narrative) (Details)

v3.6.0.2
Earnings per Share (Narrative) (Details) - shares
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Stock Options And Service Based Restricted Stock Units [Member]      
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Antidilutive securities excluded from computation of earnings per share, number of shares 517,654 154,170 409,250
Performance Based Restricted Stock Units [Member]      
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Antidilutive securities excluded from computation of earnings per share, number of shares 63,430 122,858 120,363