Segment Information (Total Assets of Reportable Segments) (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	$ 53,876,703	$ 50,383,152
Americas [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	31,742,036	29,960,387
CANADA
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	3,911,340	3,631,887
EMEA [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	6,745,951	6,920,296
Asia Pacific [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	4,499,194	3,970,058
Corporate and Other [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	6,978,182	5,900,524
Life Insurance Product Line [Member] | Americas [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	17,806,550	16,554,509
Life Insurance Product Line [Member] | CANADA
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	3,894,407	3,604,344
Life Insurance Product Line [Member] | EMEA [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	2,669,404	2,757,593
Life Insurance Product Line [Member] | Asia Pacific [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	3,757,131	3,227,530
Nontraditional Long-Duration Contracts [Member] | Americas [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	13,935,486	13,405,878
Nontraditional Long-Duration Contracts [Member] | CANADA
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	16,933	27,543
Nontraditional Long-Duration Contracts [Member] | EMEA [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	4,076,547	4,162,703
Nontraditional Long-Duration Contracts [Member] | Asia Pacific [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	$ 742,063	$ 742,528