Annual report pursuant to Section 13 and 15(d)

Earnings Per Common Share - Dilutive Shares (Details)

v3.8.0.1
Earnings Per Common Share - Dilutive Shares (Details) - shares
shares in Millions
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Common Stock      
Class of Stock [Line Items]      
Incremental common shares attributable to dilutive effect of call options and warrants (in shares) 143 150 150
Series T Preferred Stock      
Class of Stock [Line Items]      
Incremental common shares attributable to dilutive effect of conversion of preferred stock (in shares)   700 700