Segment Information (Total Assets of Reportable Segments) (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	$ 47,606,120	$ 44,679,611
Americas [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	29,735,115	25,732,075
CANADA
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	3,740,903	3,996,128
EMEA [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	4,941,994	4,693,322
Asia Pacific [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	3,761,959	3,619,368
Corporate and Other [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	5,426,149	6,638,718
Life Insurance Product Line [Member] | Americas [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	16,090,309	14,159,824
Life Insurance Product Line [Member] | CANADA
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	3,720,003	3,946,942
Life Insurance Product Line [Member] | EMEA [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	2,949,206	2,514,868
Life Insurance Product Line [Member] | Asia Pacific [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	3,028,691	2,951,723
Nontraditional Long-Duration Contracts [Member] | Americas [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	13,644,806	11,572,251
Nontraditional Long-Duration Contracts [Member] | CANADA
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	20,900	49,186
Nontraditional Long-Duration Contracts [Member] | EMEA [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	1,992,788	2,178,454
Nontraditional Long-Duration Contracts [Member] | Asia Pacific [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	$ 733,268	$ 667,645