Revenues (Tables)

12 Months Ended

Dec. 31, 2019

Revenue from Contract with Customer [Abstract]

Disaggregation of Revenue [Table Text Block]

SPS’ operating revenues consisted of the following:

(Millions of Dollars)	Year Ended Dec. 31, 2019
Major product lines
Revenue from contracts with customers:
Residential	$	351.9
C&I	800.3
Other	41.1
Total retail	1,193.3
Wholesale	361.0
Transmission	239.6
Other	3.3
Total revenue from contracts with customers	1,797.2
Alternative revenue and other	28.6
Total revenues	$	1,825.8

(Millions of Dollars)	Year Ended Dec. 31, 2018
Major product lines
Revenue from contracts with customers:
Residential	$	363.7
C&I	828.3
Other	44.7
Total retail	1,236.7
Wholesale	426.0
Transmission	231.1
Other	12.8
Total revenue from contracts with customers	1,906.6
Alternative revenue and other	26.6
Total revenues	$	1,933.2