Dividends From Subsidiaries And Statutory Financial Information (Schedule of Combined Net Income and Policyholders' Surplus in Accordance with Statutory Accounting Practices) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Insurance [Abstract]
Amount available for dividend distribution without prior approval from regulatory authorities	$ 601,000
Net income	601,564	$ 1,099,953	$ 698,862
Policyholders' surplus	6,013,062	$ 5,587,930	$ 5,479,603
Increase in BIC's statutory capital and surplus	$ 268,000
Total Adjusted Capital percentage threshold	200.00%
BIC's Total Adjusted Capital balance	$ 5,746,000
BIC's Total Adjusted Capital balance as percentage of RBC Authorized Control Level	396.00%