SCHEDULE II - CONDENSED FINANCIAL INFORMATION OF REGISTRANT - Debt and Other Obligations (Details) - USD ($)		11 Months Ended	12 Months Ended
	May 03, 2018	Dec. 31, 2015	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Aug. 10, 2017
Condensed Financial Statements, Captions [Line Items]
Outstanding Principal			$ 991,363,000	$ 784,610,000
Total debt			1,101,827,000	945,052,000
Total subordinated debt securities			605,426,000	495,289,000
Future maturities of debt, excluding notes payable to banks, and subordinated debt securities, for the next five years
Debt maturities due in 2019			416,500,000
Debt maturities due thereafter			684,000,000
Interest Expense
Interest expense			66,500,000	61,300,000	$ 62,100,000
6.40% Senior Notes (2007), due 2018
Condensed Financial Statements, Captions [Line Items]
Outstanding Principal			0	150,000,000
Total debt			$ 0	150,518,000
Stated interest rate (as a percent)			6.40%
7.375% Senior Notes (2009), due 2019
Condensed Financial Statements, Captions [Line Items]
Outstanding Principal			$ 400,000,000	400,000,000
Total debt			$ 416,469,000	435,806,000
Stated interest rate (as a percent)			7.375%
8.45% Senior Notes (2009), due 2039
Condensed Financial Statements, Captions [Line Items]
Outstanding Principal			$ 190,044,000	232,928,000
Total debt			$ 288,547,000	357,046,000
Stated interest rate (as a percent)			8.45%
Future maturities of debt, excluding notes payable to banks, and subordinated debt securities, for the next five years
Redemption of subordinated debt			$ 65,600,000
Par value of extinguished debt			42,900,000
Pre-tax gain on extinguishment			1,800,000
4.30% Senior Notes (2018), due 2028
Condensed Financial Statements, Captions [Line Items]
Outstanding Principal			400,000,000
Total debt			$ 395,492,000	0
Stated interest rate (as a percent)			4.30%
Future maturities of debt, excluding notes payable to banks, and subordinated debt securities, for the next five years
Discount on notes			$ 1,000,000
Debt issuance costs			$ 3,700,000
5.35% Subordinated Debentures (2017), due 2052
Condensed Financial Statements, Captions [Line Items]
Stated interest rate (as a percent)			5.35%
6.00% Subordinated Debentures, due 2042
Condensed Financial Statements, Captions [Line Items]
Stated interest rate (as a percent)			6.00%
6.25% Subordinated Debentures (2012), due 2042, callable 2017
Condensed Financial Statements, Captions [Line Items]
Stated interest rate (as a percent)			6.25%
2015 Credit Facility
Future maturities of debt, excluding notes payable to banks, and subordinated debt securities, for the next five years
Line of credit, maximum borrowing capacity			$ 1,000,000,000
Line of credit, maximum borrowing capacity to be granted upon entity's request			$ 1,250,000,000.00
Facility fee percentage			0.125%
2015 Credit Facility | Federal Funds Rate
Future maturities of debt, excluding notes payable to banks, and subordinated debt securities, for the next five years
Interest rate added to the base rate (as a percent)			0.50%
2015 Credit Facility | LIBOR One-Month Rate
Future maturities of debt, excluding notes payable to banks, and subordinated debt securities, for the next five years
Interest rate added to the base rate (as a percent)			1.00%
2015 Credit Facility as amended
Future maturities of debt, excluding notes payable to banks, and subordinated debt securities, for the next five years
Line of credit, maximum borrowing capacity			$ 1,000,000,000
Line of credit, maximum borrowing capacity to be granted upon entity's request	$ 1,500,000,000.0
Facility fee percentage			0.125%
2015 Credit Facility as amended | Federal Funds Rate
Future maturities of debt, excluding notes payable to banks, and subordinated debt securities, for the next five years
Interest rate added to the base rate (as a percent)			0.50%
2015 Credit Facility as amended | LIBOR One-Month Rate
Future maturities of debt, excluding notes payable to banks, and subordinated debt securities, for the next five years
Interest rate added to the base rate (as a percent)			1.00%
PROTECTIVE LIFE CORPORATION
Condensed Financial Statements, Captions [Line Items]
Outstanding Principal			$ 990,044,000	782,928,000
Total debt			1,100,508,000	943,370,000
Total subordinated debt securities			495,426,000	495,289,000
Future maturities of debt, excluding notes payable to banks, and subordinated debt securities, for the next five years
Debt maturities due in 2019			416,500,000
Debt maturities due thereafter			684,000,000
PROTECTIVE LIFE CORPORATION | 6.40% Senior Notes (2007), due 2018
Condensed Financial Statements, Captions [Line Items]
Outstanding Principal			0	150,000,000
Total debt			$ 0	150,518,000
Stated interest rate (as a percent)			6.40%
PROTECTIVE LIFE CORPORATION | 7.375% Senior Notes (2009), due 2019
Condensed Financial Statements, Captions [Line Items]
Outstanding Principal			$ 400,000,000	400,000,000
Total debt			$ 416,469,000	435,806,000
Stated interest rate (as a percent)			7.375%
PROTECTIVE LIFE CORPORATION | 8.45% Senior Notes (2009), due 2039
Condensed Financial Statements, Captions [Line Items]
Outstanding Principal			$ 190,044,000	232,928,000
Total debt			$ 288,547,000	357,046,000
Stated interest rate (as a percent)			8.45%
Future maturities of debt, excluding notes payable to banks, and subordinated debt securities, for the next five years
Redemption of subordinated debt			$ 65,600,000
Par value of extinguished debt			42,900,000
Pre-tax gain on extinguishment			1,800,000
PROTECTIVE LIFE CORPORATION | 4.30% Senior Notes (2018), due 2028
Condensed Financial Statements, Captions [Line Items]
Outstanding Principal			400,000,000
Total debt			$ 395,492,000	0
Stated interest rate (as a percent)			4.30%
Future maturities of debt, excluding notes payable to banks, and subordinated debt securities, for the next five years
Discount on notes			$ 1,000,000
PROTECTIVE LIFE CORPORATION | 5.35% Subordinated Debentures (2017), due 2052
Condensed Financial Statements, Captions [Line Items]
Stated interest rate (as a percent)			5.35%
PROTECTIVE LIFE CORPORATION | 6.00% Subordinated Debentures, due 2042
Condensed Financial Statements, Captions [Line Items]
Stated interest rate (as a percent)						6.00%
PROTECTIVE LIFE CORPORATION | 6.25% Subordinated Debentures (2012), due 2042, callable 2017
Condensed Financial Statements, Captions [Line Items]
Stated interest rate (as a percent)						6.25%
PROTECTIVE LIFE CORPORATION | 2015 Credit Facility
Future maturities of debt, excluding notes payable to banks, and subordinated debt securities, for the next five years
Line of credit, maximum borrowing capacity	1,000,000,000.0
Line of credit, maximum borrowing capacity to be granted upon entity's request	$ 1,250,000,000.00
Facility fee percentage	0.125%
PROTECTIVE LIFE CORPORATION | 2015 Credit Facility | Federal Funds Rate
Future maturities of debt, excluding notes payable to banks, and subordinated debt securities, for the next five years
Interest rate added to the base rate (as a percent)	0.50%
PROTECTIVE LIFE CORPORATION | 2015 Credit Facility | LIBOR One-Month Rate
Future maturities of debt, excluding notes payable to banks, and subordinated debt securities, for the next five years
Interest rate added to the base rate (as a percent)	1.00%
PROTECTIVE LIFE CORPORATION | 2015 Credit Facility as amended
Future maturities of debt, excluding notes payable to banks, and subordinated debt securities, for the next five years
Line of credit, maximum borrowing capacity	$ 1,000,000,000.0
Line of credit, maximum borrowing capacity to be granted upon entity's request	$ 1,500,000,000.0
Facility fee percentage	0.125%
PROTECTIVE LIFE CORPORATION | 2015 Credit Facility as amended | Federal Funds Rate
Future maturities of debt, excluding notes payable to banks, and subordinated debt securities, for the next five years
Interest rate added to the base rate (as a percent)	0.50%
PROTECTIVE LIFE CORPORATION | 2015 Credit Facility as amended | LIBOR One-Month Rate
Future maturities of debt, excluding notes payable to banks, and subordinated debt securities, for the next five years
Interest rate added to the base rate (as a percent)	1.00%
PROTECTIVE LIFE CORPORATION | Long-term debt and subordinated debt securities
Interest Expense
Interest expense		$ 60,100,000	$ 63,900,000	61,300,000
Credit Facility | PROTECTIVE LIFE CORPORATION
Condensed Financial Statements, Captions [Line Items]
Outstanding Principal			0	0
Total debt			0	0
Subordinated debentures
Condensed Financial Statements, Captions [Line Items]
Outstanding Principal			610,000,000	500,000,000
Total subordinated debt securities			605,426,000	495,289,000
Subordinated debentures | 5.35% Subordinated Debentures (2017), due 2052
Condensed Financial Statements, Captions [Line Items]
Outstanding Principal			500,000,000	500,000,000
Total subordinated debt securities			495,426,000	495,289,000
Subordinated debentures | PROTECTIVE LIFE CORPORATION
Condensed Financial Statements, Captions [Line Items]
Outstanding Principal			500,000,000	500,000,000
Total subordinated debt securities			495,426,000	495,289,000
Subordinated debentures | PROTECTIVE LIFE CORPORATION | 4.30% Senior Notes (2018), due 2028
Future maturities of debt, excluding notes payable to banks, and subordinated debt securities, for the next five years
Debt issuance costs			3,700,000
Subordinated debentures | PROTECTIVE LIFE CORPORATION | 5.35% Subordinated Debentures (2017), due 2052
Condensed Financial Statements, Captions [Line Items]
Outstanding Principal			500,000,000.0	500,000,000
Total subordinated debt securities			495,426,000	495,289,000
Future maturities of debt, excluding notes payable to banks, and subordinated debt securities, for the next five years
Debt issuance costs			$ 4,800,000
Subordinated debentures | PROTECTIVE LIFE CORPORATION | 6.00% Subordinated Debentures, due 2042
Condensed Financial Statements, Captions [Line Items]
Outstanding Principal				150,000,000
Subordinated debentures | PROTECTIVE LIFE CORPORATION | 6.25% Subordinated Debentures (2012), due 2042, callable 2017
Condensed Financial Statements, Captions [Line Items]
Outstanding Principal				$ 287,500,000