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Investments (Other Investment Portfolio by Strategy and the Remaining Commitment Amount Associated With Each Strategy) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Carrying Value	$ 77,842	$ 99,203
Alternative Investments [Member]
Carrying Value	67,834	92,968
Remaining Commitment	71,153
Other Investment Portfolio [Member]
Carrying Value	77,842	99,203
Remaining Commitment	74,353
Secondary Private Equity [Member] | Alternative Investments [Member]
Carrying Value	35,088	48,538
Remaining Commitment	30,204
Private Equity [Member] | Alternative Investments [Member]
Carrying Value	13,246	18,533
Remaining Commitment	15,129
Energy Power Generation [Member] | Alternative Investments [Member]
Carrying Value	19,500	25,897
Remaining Commitment	25,820
Other Securities [Member]
Carrying Value	10,008	$ 6,235
Remaining Commitment	$ 3,200

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- Definition

This item represents contractual obligations to invest additional amounts on our other investment portfolio. These additional investments may or may not be required.

+ References

No definition available.

+ Details

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- Definition

Other investments not otherwise specified in the taxonomy.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.12)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.1(f,g))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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