Revenue and Contracts with Customers (Tables)

3 Months Ended

Mar. 31, 2021

Revenue from Contract with Customer [Abstract]

Revenue from External Customers by Geographic Areas

The following table presents revenue from separative work units (“SWU”) and uranium sales disaggregated by geographical region based on the billing addresses of customers (in millions):

	Three Months Ended March 31,
	2021		2020
United States	$	9.6	$	7.3
Foreign	28.5		23.4
Revenue - SWU and uranium	$	38.1	$	30.7

Contract with Customer, Asset and Liability

	March 31, 2021		December 31, 2020		Year-To-Date Change
Accrued loss on HALEU Contract:
Current - Accounts payable and accrued liabilities	$	5.7	$	7.0	$	(1.3)
Noncurrent - Other long-term liabilities	$	—	$	0.7	$	(0.7)
Deferred revenue - current	$	253.5	$	281.7	$	(28.2)
Advances from customers - current	$	2.0	$	1.5	$	0.5
Advances from customers - noncurrent	$	44.4	$	45.2	$	(0.8)