Segment Information (Total Revenues of Reportable Segments) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	$ 2,900,577	$ 2,438,634	$ 8,452,213	$ 7,589,587
Americas [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	1,721,052	1,399,737	4,959,854	4,381,723
CANADA
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	293,318	252,478	862,768	810,904
EMEA [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	388,822	353,588	1,128,831	1,063,696
Asia Pacific [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	446,684	433,390	1,355,570	1,265,225
Corporate and Other [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	50,701	(559)	145,190	68,039
Life Insurance Product Line [Member] | Americas [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	1,444,917	1,312,638	4,339,737	3,910,176
Life Insurance Product Line [Member] | CANADA
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	280,959	241,438	827,871	776,532
Life Insurance Product Line [Member] | EMEA [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	289,070	284,350	880,346	863,774
Life Insurance Product Line [Member] | Asia Pacific [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	427,647	421,970	1,299,417	1,227,159
Nontraditional Long-Duration Contracts [Member] | Americas [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	276,135	87,099	620,117	471,547
Nontraditional Long-Duration Contracts [Member] | CANADA
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	12,359	11,040	34,897	34,372
Nontraditional Long-Duration Contracts [Member] | EMEA [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	99,752	69,238	248,485	199,922
Nontraditional Long-Duration Contracts [Member] | Asia Pacific [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	$ 19,037	$ 11,420	$ 56,153	$ 38,066