CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME
Net income and comprehensive income	$ 1,577.8	$ 1,491.9	$ 1,548.2
Other comprehensive income (loss) net of tax:
-Decrease (increase) in pension and other post-retirement benefits (net of income tax of $(1.9), $3.7 and $2.1, respectively)	1.7	(7.7)	(2.9)
Total other comprehensive income (loss)	1.7	(7.7)	(2.9)
Total comprehensive income	1,579.5	1,484.2	1,545.3
Comprehensive income attributable to the non-controlling interest	7.4	6.1	5.2
Comprehensive income attributable to SCC	$ 1,572.1	$ 1,478.1	$ 1,540.1