XML 76 R35.htm IDEA: XBRL DOCUMENT v3.10.0.1
Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Tables)
 12 Months Ended
Sep. 30, 2018
Accounting Policies [Abstract]  
Property, Plant, and Equipment Depreciation Rates
Average depreciation rates by asset class are as follows:
Property, Plant, and Equipment Depreciation Rates
At September 30
(percent)
 
2018
 
2017
 
2016
Asset Class
 
 
 
 
 
Nuclear
2.64

 
2.66

 
2.37

Coal-fired
2.32

 
2.33

 
3.50

Hydroelectric
1.57

 
1.58

 
1.29

Gas and oil-fired
2.93

 
3.27

 
3.09

Transmission
1.32

 
1.34

 
2.80

Other
5.90

 
6.12

 
8.97