Annual report pursuant to Section 13 and 15(d)

Earnings (Loss) per Common Share (Anti-Dilutive Weighted Average Shares Outstanding) (Details)

v3.8.0.1
Earnings (Loss) per Common Share (Anti-Dilutive Weighted Average Shares Outstanding) (Details) - shares
shares in Thousands
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Total excluded 1,897 3 858
Derivative instrument that may be settled in cash or shares      
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Total excluded 1,870 0 724
Shares associated with unexercised stock options      
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Total excluded 1 3 108
Share-based compensation that may be settled in cash or shares      
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Total excluded 26 0 26