XML 16 R5.htm IDEA: XBRL DOCUMENT v3.10.0.1
CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($)
$ in Millions
Jun. 30, 2018
Dec. 31, 2017
Statement of Financial Position [Abstract]    
Accounts receivable and accrued unbilled revenues, reserves $ 157.5 $ 143.2
Property, plant, and equipment, accumulated depreciation $ 8,512.1 $ 8,618.5
Common stock, par value (in dollars per share) $ 0.01 $ 0.01
Common stock, shares authorized 325,000,000 325,000,000
Common stock, shares outstanding 315,533,448 315,574,624