Retrocession Arrangements and Reinsurance Ceded Receivables (Narrative) (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended	12 Months Ended
Sep. 30, 2013	Dec. 31, 2012
Retrocession Arrangements And Reinsurance Ceded Receivables [Abstract]
Retrocession Pool Participants Minimum AM Best Rating	A- (excellent)	A- (excellent)
Reinsurance Claims Recoverables	$ 132.4	$ 156.0
Claims Recoverable From Retrocessionaires Past Due	$ 6.5	$ 10.4

The known and estimated amount recoverable as of the balance sheet date from reinsurers for claims paid or incurred by the ceding insurer and associated claims settlement expenses, including estimated amounts for claims incurred but not reported, and policy benefits, net of any related valuation allowance.

No definition available.

Name:	rga_ReinsuranceClaimsRecoverables
Namespace Prefix:	rga_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant