Schedule IV - Reinsurance (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Sep. 30, 2012	Sep. 30, 2011
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Gross Amount	$ 415,845	$ 226,208
Ceded to other companies	(369,449)	(160,404)
Assumed from other companies	47,179	22,858
Net Amount	93,575	88,662
Percentage of amount assumed to net	50.42%	25.78%
Life insurance in force [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Gross Amount	2,436,312	2,256,696
Ceded to other companies	(1,929,017)	(1,180,412)
Assumed from other companies	22,812	22,641
Net Amount	530,107	1,098,925
Percentage of amount assumed to net	4.30%	2.06%
Premiums and other considerations [Member] \| Traditional life insurance premiums [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Gross Amount	297,964	157,772
Ceded to other companies	(289,846)	(141,628)
Assumed from other companies	47,179	22,858
Net Amount	55,297	39,002
Percentage of amount assumed to net	85.32%	58.61%
Premiums and other considerations [Member] \| Annuity product charges [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Gross Amount	117,881	68,436
Ceded to other companies	(79,603)	(18,776)
Net Amount	$ 38,278	$ 49,660
Percentage of amount assumed to net	0.00%	0.00%

Amount of premiums assumed from other companies.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 17

-Article 12

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 235

-Section S99

-Paragraph 2

-Subparagraph (SX 210.12-17)

-URI http://asc.fasb.org/extlink&oid=6588446&loc=d3e574992-122915

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