Accumulation Units - Schedule of changes in the number of accumulation units outstanding (Details) - shares shares in Millions	3 Months Ended	6 Months Ended
	Mar. 31, 2022	Jun. 30, 2021
Outstanding:
Beginning of period (in shares)	53.4	52.0
Credited for premiums (in shares)	1.5	6.4
Annuity, other periodic payments, withdrawals and death benefits (in shares)	(1.2)	(5.0)
End of period (in shares)	53.7