Segment Information (Total Revenues of Reportable Segments) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	$ 3,039,068	$ 2,630,340	$ 5,551,636	$ 5,150,953
Americas [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	1,799,080	1,534,023	3,238,802	2,981,986
CANADA
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	300,766	281,548	569,450	558,426
EMEA [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	382,619	359,500	740,009	710,108
Asia Pacific [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	494,616	418,390	908,886	831,835
Corporate and Other [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	61,987	36,879	94,489	68,598
Life Insurance Product Line [Member] | Americas [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	1,494,003	1,342,248	2,894,820	2,597,538
Life Insurance Product Line [Member] | CANADA
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	288,912	270,090	546,912	535,094
Life Insurance Product Line [Member] | EMEA [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	301,642	284,192	591,276	579,424
Life Insurance Product Line [Member] | Asia Pacific [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	477,571	411,314	871,770	805,189
Nontraditional Long-Duration Contracts [Member] | Americas [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	305,077	191,775	343,982	384,448
Nontraditional Long-Duration Contracts [Member] | CANADA
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	11,854	11,458	22,538	23,332
Nontraditional Long-Duration Contracts [Member] | EMEA [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	80,977	75,308	148,733	130,684
Nontraditional Long-Duration Contracts [Member] | Asia Pacific [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	$ 17,045	$ 7,076	$ 37,116	$ 26,646