Derivatives (Narrative) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	$ 7,896,000		$ 8,656,000
Derivative Liability, Fair Value, Gross Liability	0		0
Cash collateral on derivative assets	655,000		0
Derivative, Net Liability Position, Aggregate Fair Value	0		0
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Discontinuation of Cash Flow Hedge Due to Forecasted Transaction Probable of Not Occurring, Net	0	$ 0
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months	486,000
Embedded derivatives gains (losses)	(131,329,000)	49,158,000
Derivative Instrument Detail [Abstract]
Accumulated Other Comprehensive Income (Loss)	4,300,000		4,700,000
Securities collateral received which the company is permitted to sell or repledge, amount that has been sold or repledged	0
Direct And Assumed Guaranteed Minimum Benefit [Member] | Nonperformance Risk [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Embedded derivatives gains (losses)	(300,000)	1,700,000
Ceded guaranteed minimum benefits | Nonperformance Risk [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Embedded derivatives gains (losses)	7,000,000	(17,800,000)
Currency Swap [Member] | Cash Flow Hedges
Derivative Instruments, Gain (Loss) [Line Items]
Gains Losses Deferred In Accumulated Other Comprehensive Income Loss On Derivatives Effective Portion	(421,000)	(146,000)
Net Derivative Gain (Loss) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Embedded derivatives gains (losses)	(131,329,000)	49,158,000
Net Derivative Gain (Loss) [Member] | Cash Flow Hedges
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	0	0
Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net	1,000	0
Over the Counter [Member]
Derivatives, Fair Value [Line Items]
Derivative, Collateral, Right to Reclaim Securities	0		0
Cash collateral on derivative assets	(8,087,000)		(8,672,000)
Derivative, Collateral, Obligation to Return Securities	0		0
Not Designated as Hedging Instrument [Member] | Currency Swap [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	3,370,000		3,709,000
Derivative Liability, Fair Value, Gross Liability	0		0
Not Designated as Hedging Instrument [Member] | Net Derivative Gain (Loss) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Interest Income (Expense), Nonoperating, Net	84,000	63,000
Not Designated as Hedging Instrument [Member] | Foreign Exchange [Member] | Net Derivative Gain (Loss) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	(339,000)	94,000
Designated as Hedging Instrument [Member] | Currency Swap [Member] | Cash Flow Hedges
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	4,526,000		4,947,000
Derivative Liability, Fair Value, Gross Liability	0		0
Designated as Hedging Instrument [Member] | Net investment income
Derivative Instruments, Gain (Loss) [Line Items]
Interest Income (Expense), Nonoperating, Net	124,000	$ 148,000
Accrued Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	$ 266,000		$ 194,000