Annual and transition report of foreign private issuers pursuant to Section 13 or 15(d)

Earnings per Share (Narrative) (Details)

Earnings per Share (Narrative) (Details) - shares
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Share Awards [Member]      
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Anti-dilutive shares, excluded from computation of diluted net loss per share 3,100,000 3,800,000 2,400,000