EARNINGS PER SHARE (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Calculation of basic earnings per share:
Net income available to PLC's common shareowners	$ 66,796	$ 60,480	$ 76,155	$ 99,021	$ 86,034	$ 82,857	$ 87,623	$ 58,878	$ 302,452	[1]	$ 315,392	[1]	$ 225,314	[1]
Average shares issued and outstanding									80,149,261		84,309,804		85,638,080
Issuable under various deferred compensation plans (in shares)									917,077		898,808		928,989
Weighted shares outstanding - basic	79,652,495	80,662,745	81,639,756	82,330,330	83,205,456	84,722,232	86,346,216	86,603,228	81,066,338		85,208,612		86,567,069
Per share:
Net income available to PLC's common shareowners - basic (in dollars per share)	$ 0.84	$ 0.75	$ 0.93	$ 1.20	$ 1.03	$ 0.98	$ 1.01	$ 0.68	$ 3.73		$ 3.70		$ 2.60
Calculation of diluted earnings per share:
Net income available to PLC's common shareowners	$ 66,796	$ 60,480	$ 76,155	$ 99,021	$ 86,034	$ 82,857	$ 87,623	$ 58,878	$ 302,452	[1]	$ 315,392	[1]	$ 225,314	[1]
Weighted shares outstanding - basic	79,652,495	80,662,745	81,639,756	82,330,330	83,205,456	84,722,232	86,346,216	86,603,228	81,066,338		85,208,612		86,567,069
Stock appreciation rights ("SARs") (in shares)									448,936		468,810		467,170
Issuable under various other stock-based compensation plans (in shares)									588,298		122,027		134,379
Restricted stock units (in shares)									619,444		675,780		507,239
Weighted shares outstanding - diluted	81,339,803	82,406,103	83,243,703	83,921,135	84,464,572	86,004,571	87,653,731	87,820,085	82,723,016		86,475,229		87,675,857
Per share:
Net income available to PLC's common shareowners - diluted (in dollars per share)	$ 0.82	$ 0.73	$ 0.91	$ 1.18	$ 1.02	$ 0.96	$ 1.00	$ 0.67	$ 3.66		$ 3.65		$ 2.57
Antidilutive securities (in shares)									670,320		1,440,047		1,455,395

[1] Protective Life Corporation ("PLC")