Segment Information (Total Assets of Reportable Segments) (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	$ 47,460,271	$ 44,679,611
Americas [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	29,758,824	25,732,075
CANADA
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	3,830,720	3,996,128
EMEA [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	4,650,948	4,693,322
Asia Pacific [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	3,622,467	3,619,368
Corporate and Other [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	5,597,312	6,638,718
Life Insurance Product Line [Member] | Americas [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	15,904,747	14,159,824
Life Insurance Product Line [Member] | CANADA
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	3,805,372	3,946,942
Life Insurance Product Line [Member] | EMEA [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	2,586,327	2,514,868
Life Insurance Product Line [Member] | Asia Pacific [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	2,997,342	2,951,723
Nontraditional Long-Duration Contracts [Member] | Americas [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	13,854,077	11,572,251
Nontraditional Long-Duration Contracts [Member] | CANADA
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	25,348	49,186
Nontraditional Long-Duration Contracts [Member] | EMEA [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	2,064,621	2,178,454
Nontraditional Long-Duration Contracts [Member] | Asia Pacific [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	$ 625,125	$ 667,645