Guarantees (Changes in liabilty of estimated loss from credit recourse agreement) (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2017	Mar. 31, 2016
Movement In Guaranteed Benefit Liability Gross Roll Forward
Balance at beginning of the period	$ 710	$ 439
Net charge-off/terminations	(140)	(258)
Balance at the end of the period	$ 570	$ 181

Amount of guaranteed minimum benefit payments to policyholders and contract holders, during the period presented, resulting in a decrease to the liability for expected guaranteed minimum benefits in excess of projected account values.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 20
-Section 55
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=6588021&loc=d3e7104-158389

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 80
-Section 50
-Paragraph 1
-Subparagraph (d)(4)
-URI http://asc.fasb.org/extlink&oid=6484115&loc=d3e19393-158473

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of expected guaranteed benefits in excess of the projected account balances for minimum guaranteed benefit contracts, as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 20
-Section 55
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=6588021&loc=d3e7104-158389

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 80
-Section 50
-Paragraph 1
-Subparagraph (d)(3)
-URI http://asc.fasb.org/extlink&oid=6484115&loc=d3e19393-158473

+ Details

Name:	us-gaap_LiabilitiesForGuaranteesOnLongDurationContractsGuaranteedBenefitLiabilityGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

Name:	us-gaap_MovementInGuaranteedBenefitLiabilityGrossRollForward
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration