DEFERRED POLICY ACQUISITION COSTS AND VALUE OF BUSINESS ACQUIRED (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended				12 Months Ended
	Mar. 31, 2012		Mar. 31, 2011		Dec. 31, 2011
Assets
Deferred policy acquisition costs and value of business acquired	$ 3,234,596				$ 3,248,041	[1]
Total assets	53,322,272				52,143,369	[1]
Liabilities
Deferred income taxes	1,241,670				1,260,629	[1]
Total liabilities	49,537,212				48,432,602	[1]
Equity:
Retained earnings	2,277,267				2,191,319	[1]
Accumulated other comprehensive income (loss):
Net unrealized gain (losses) on investments, net of income tax	1,103,126				1,094,103	[1]
Total equity	3,785,060				3,710,767	[1]
Total liabilities and shareowners' equity	53,322,272				52,143,369	[1]
Expenses
Amortization of deferred policy acquisition costs and value of business acquired	56,836		65,226	[1]
Other operating expenses	155,137		144,771	[1]
Total benefits and expenses	801,602		746,366	[1]
Income before income tax	150,579		90,714	[1]
Income tax (benefit) expense	51,558		31,887	[1]
Net income	99,021		58,827	[1]
Less: Net income (loss) attributable to noncontrolling interests			(51)	[1]
Net income available to PLC's common shareowners (2)	99,021	[2]	58,878	[1],[2]
Net income available to PLC's common shareowners - basic (in dollars per share)	$ 1.20		$ 0.68	[1]
Net income available to PLC's common shareowners - diluted (in dollars per share)	$ 1.18		$ 0.67	[1]
Cash flows from operating activities
Net income	99,021		58,827	[1]
Amortization of deferred policy acquisition costs and value of business acquired	56,836		65,226	[1]
Capitalization of deferred policy acquisition costs	(63,971)		(95,560)	[1]
Deferred income tax	(23,126)		18,573	[1]
Other, net	4,899		(15,289)	[1]
Net cash provided by operating activities			31,777
Balances and changes in DAC
Balance, beginning of period	2,219,901		2,124,329		2,124,329
Capitalization of commissions, sales and issue expenses	65,369				370,830
Amortization	(45,556)				(215,600)
Change in unrealized investment gains and losses	(10,338)				(59,658)
Balance, end of period	2,229,384				2,219,901
Balances and changes in VOBA
Balance, beginning of period	1,028,140		968,253		968,253
Acquisitions					137,418
Amortization	(12,692)				(66,163)
Change in unrealized gains and losses	(10,236)				(21,907)
Other					10,539
Balance, end of period	1,005,212				1,028,140
As originally reported
Assets
Deferred policy acquisition costs and value of business acquired					4,036,757
Total assets					52,932,085
Liabilities
Deferred income taxes					1,540,397
Total liabilities					48,712,370
Equity:
Retained earnings					2,719,492
Accumulated other comprehensive income (loss):
Net unrealized gain (losses) on investments, net of income tax					1,074,878
Total equity					4,219,715
Total liabilities and shareowners' equity					52,932,085
Expenses
Amortization of deferred policy acquisition costs and value of business acquired			74,363
Other operating expenses			122,253
Total benefits and expenses			732,985
Income before income tax			104,095
Income tax (benefit) expense			36,629
Net income			67,466
Less: Net income (loss) attributable to noncontrolling interests			(51)
Net income available to PLC's common shareowners (2)			67,517
Net income available to PLC's common shareowners - basic (in dollars per share)			$ 0.78
Net income available to PLC's common shareowners - diluted (in dollars per share)			$ 0.77
Cash flows from operating activities
Net income			67,466
Amortization of deferred policy acquisition costs and value of business acquired			74,363
Capitalization of deferred policy acquisition costs			(118,078)
Deferred income tax			23,314
Other, net			(15,288)
Net cash provided by operating activities			31,777
ASU No. 2010-26 | Effect of change
Assets
Deferred policy acquisition costs and value of business acquired					(788,716)
Total assets					(788,716)
Liabilities
Deferred income taxes					(279,768)
Total liabilities					(279,768)
Equity:
Retained earnings					(528,173)
Accumulated other comprehensive income (loss):
Net unrealized gain (losses) on investments, net of income tax					19,225
Total equity					(508,948)
Total liabilities and shareowners' equity					(788,716)
Expenses
Amortization of deferred policy acquisition costs and value of business acquired			(9,137)
Other operating expenses			22,518
Total benefits and expenses			13,381
Income before income tax			(13,381)
Income tax (benefit) expense			(4,742)
Net income			(8,639)
Net income available to PLC's common shareowners (2)			(8,639)
Net income available to PLC's common shareowners - basic (in dollars per share)			$ (0.10)
Net income available to PLC's common shareowners - diluted (in dollars per share)			$ (0.10)
Cash flows from operating activities
Net income			(8,639)
Amortization of deferred policy acquisition costs and value of business acquired			(9,137)
Capitalization of deferred policy acquisition costs			22,518
Deferred income tax			(4,741)
Other, net			$ (1)

[1] Recast from previously reported information

[2] Protective Life Corporation ("PLC")