- Narrative (Details)		12 Months Ended
		Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 21, 2017 USD ($)
Letter of Credit
Related Party Transaction [Line Items]
Amount outstanding		$ 0
GWL&A Financial
Related Party Transaction [Line Items]
Interest payable	[1]	602,920,000
GWL&A Financial | Letter of Credit
Related Party Transaction [Line Items]
Letter of credit		70,000,000
Amount of terminated letter of credit					$ 1,141,000,000
Amount outstanding		$ 70,000,000	$ 0
GWL&A Financial | Surplus Notes Payable
Related Party Transaction [Line Items]
Minimum multiple required to be applied on authorized control level at the time of payments of principal and interest		2.5
Interest expense attributable to related party debt obligations		$ 25,773,000	29,185,000	$ 37,059,000
Interest payable		3,409,000	3,190,000
CLAC
Related Party Transaction [Line Items]
Funds withheld assets		$ 503,258,000	511,575,000
Interest rate on the funds withheld		4.55%
Interest Income, related party		$ 21,813,000	22,045,000	22,165,000
Entities Affiliated to Subsidiaries
Related Party Transaction [Line Items]
Related party purchased in interest annuity contracts		292,774,000	183,365,000	$ 146,547,000
Related party reduction of separate account assets and liabilities		$ 335,311,000	$ 302,898,000

[1] Related party long-term debt interest - One long-term surplus note bears interest at a fixed rate through maturity. The second surplus note bears a variable interest rate plus the then-current three-month London Interbank Offering Rate (“LIBOR”). The third long-term surplus note bears interest at a fixed rate through maturity. The interest payments shown in this table are calculated based upon the contractual rates in effect on December 31, 2017 and do not consider the impact of future interest rate changes.