Employee Benefit Plans (Schedule of Changes in Projected Benefit Obligations) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Defined Benefit Plan, Benefit Obligation, Beginning Balance		$ 161,955
Defined Benefit Plan, Benefit Obligation, Ending Balance		172,143		$ 161,955
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Defined Benefit Plan, Benefit Obligation, Beginning Balance		161,955		142,239
Defined Benefit Plan, Service Cost		10,686		10,319		$ 9,222
Defined Benefit Plan, Interest Cost		5,326		4,790		5,035
Defined Benefit Plan, Contributions by Plan Participants (Deprecated 2017-01-31)		0		0
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Plan Amendment	[2]	159	[1]	0	[1]	0
Defined Benefit Plan, Actuarial Net (Gains) Losses		11,336		9,973
Defined Benefit Plan Settlement Gain Loss		(438)		258
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Settlement		(12,907)		3,152
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31)		(5,974)		(3,047)
Defined Benefit Plan, Foreign Currency Exchange Rate Changes, Benefit Obligation		2,000		575
Defined Benefit Plan, Benefit Obligation, Ending Balance		172,143		161,955		142,239
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Defined Benefit Plan, Benefit Obligation, Beginning Balance		60,524		63,307
Defined Benefit Plan, Service Cost		2,543		2,883		4,062
Defined Benefit Plan, Interest Cost		2,118		2,259		2,572
Defined Benefit Plan, Contributions by Plan Participants (Deprecated 2017-01-31)		354		305
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Plan Amendment	[2]	0	[1]	(13,743)	[1]	0
Defined Benefit Plan, Actuarial Net (Gains) Losses		5,510		6,228
Defined Benefit Plan Settlement Gain Loss		0		0
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Settlement		0		0
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31)		(851)		(715)
Defined Benefit Plan, Foreign Currency Exchange Rate Changes, Benefit Obligation		0		0
Defined Benefit Plan, Benefit Obligation, Ending Balance		$ 70,198		$ 60,524		$ 63,307

[1] Reflects effect of the amendment to RGA’s U.S. retiree health care benefit plan announced in 2016, effective January 1, 2017 and other administrative amendments to the pension plans. The amounts were recorded in AOCI and will be amortized through prior service cost.

[2] Reflects effect of the amendment to RGA’s U.S. retiree health care benefit plan announced in 2016, effective January 1, 2017 and other administrative amendments to the pension plans. The amounts were recorded in AOCI and will be amortized through prior service cost.