Related Party Transactions	12 Months Ended
	Dec. 31, 2020
Related Party Transactions [Abstract]
Related Party Transactions	Related Party TransactionsThe Company reimburses Loews for, or pays directly, fees and expenses of investment facilities and services provided to the Company. Additionally, the Company provides investment-related processing services to Loews and charges Loews for these services. The net amounts incurred by the Company for these fees, expenses and services were $47 million, $44 million and $43 million for the years ended December 31, 2020, 2019 and 2018. Net amounts due to Loews related to these services, included in Other liabilities and payable in the first quarter of the subsequent year, were $22 million and $21 million as of December 31, 2020 and 2019. In addition, the Company reimbursed Loews for general corporate services and related travel expenses of less than $1 million and $1 million for the years ended December 31, 2020 and 2019. The CNA Tax Group is included in the consolidated federal income tax return of Loews and its eligible subsidiaries. The related payable due to Loews, included in Other liabilities, was $67 million as of December 31, 2020. The related receivable from Loews, included in Other assets, was $21 million as of December 31, 2019. For a detailed description of the income tax agreement with Loews see Note D to the Consolidated Financial Statements. In addition, the Company writes, at standard rates, a limited amount of insurance for Loews and its subsidiaries. The earned premiums for each of the years ended December 31, 2020, 2019 and 2018 were $2 million.