Goodwill, Intangible Assets and Deferred Charge - Summary of Estimated Amortization Expense of Intangible Assets (Detail) $ in Thousands	Dec. 31, 2015 USD ($)
Finite-Lived Intangible Assets [Line Items]
2016	$ 17,831
2017	19,857
2018	16,968
2019	16,021
2020	15,831
Non-Life Run-Off Segment
Finite-Lived Intangible Assets [Line Items]
2016	8,464
2017	9,390
2018	9,128
2019	8,736
2020	8,388
Atrium
Finite-Lived Intangible Assets [Line Items]
2016	(1,193)
2017	38
2018	749
2019	1,198
2020	1,491
StarStone Segment
Finite-Lived Intangible Assets [Line Items]
2016	2,682
2017	3,097
2018	539
2019	(231)
2020	(132)
Life and Annuities
Finite-Lived Intangible Assets [Line Items]
2016	7,878
2017	7,332
2018	6,552
2019	6,318
2020	$ 6,084

Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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