XML 56 R143.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Investment in Transmission Affiliates - ATC Summarized Financial Data (Details) - ATC - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Income statement data      
Revenues $ 744.4 $ 690.5 $ 721.7
Operating expenses 373.5 358.7 345.0
Other expense 110.5 108.3 104.1
Net income 260.4 223.5 $ 272.6
Balance sheet data      
Current assets 84.7 87.2  
Noncurrent assets 5,244.2 4,928.8  
Total assets 5,328.9 5,016.0  
Current liabilities 502.6 640.0  
Long-term debt 2,312.8 2,014.0  
Other noncurrent liabilities 298.9 295.3  
Shareholders' equity 2,214.6 2,066.7  
Total liabilities and shareholders' equity $ 5,328.9 $ 5,016.0