Document and Entity Information	6 Months Ended
	Jun. 30, 2013	Aug. 01, 2013
Document and Entity Information
Entity Registrant Name	GREAT WEST LIFE & ANNUITY INSURANCE CO
Entity Central Index Key	0000744455
Document Type	10-Q
Document Period End Date	Jun. 30, 2013
Amendment Flag	true
Amendment Description	EXPLANATORY NOTE Great-West Life & Annuity Insurance Company (GWLA) and its subsidiaries (collectively, the Company) is filing this Amendment No. 1 to amend the Company's Quarterly Report on Form 10-Q for the quarter ended June 30, 2013, originally filed with the Securities and Exchange Commission (the SEC) on August 5, 2013 (the Original Filing). The Amendment restates the Company's unaudited condensed consolidated financial statements and related disclosures for the three and six months ended June 30, 2013 and 2012 and as of June 30, 2013. This Amendment also amends certain other Items in the Original Filing, as listed in Items Amended in this Amendment below, as a result of the restatement. Details of the impact of this restatement are discussed below and in Note 2 to the accompanying unaudited condensed consolidated financial statements. Restatement Background As disclosed in the Company's Form 8-K filed with the SEC on November, 14 2013, the Company determined that its unaudited condensed consolidated financial statements for the three and six months ended June 30, 2013 and 2012 and as of June 30, 2013 contained misstatements with respect to the accounting for forward settling to be announced (TBA) security transactions, plan sponsor expense accounts, and deferred acquisition costs (DAC) and should no longer be relied upon. As a result, the Company has restated the Company's previously reported unaudited condensed consolidated financial statements for the three and six months ended June 30, 2013 and 2012 and as of June 30, 2013 to reflect the following: Management has determined that certain of its forward settling TBA security transactions should have been accounted for as derivative instruments as the Company did not regularly accept delivery of such securities when issued. The Company has previously accounted for the forward settling TBA security transactions as secured borrowings. As a result, the Company has restated its condensed consolidated balance sheet to reflect the value at period end as the value of the forward derivative rather than the acquisition cost of the security as previously reported. The Company has also restated its condensed consolidated statements of income to record the mark-to-market adjustment through net income rather than through other comprehensive income. The Company also restated its condensed consolidated statements of cash flows to conform to the changes made in the condensed consolidated balance sheets and condensed consolidated statements of income. This misstatement impacts the unaudited condensed consolidated financial statements for the three and six months ended June 30, 2013 and 2012 and as of June 30, 2013. The Company's forward settling TBA securities were closed by year-end; accordingly, there are no effects of the misstatement on the consolidated balance sheet as of December 31, 2012. As a result of the decision to restate prior periods, the Company has also corrected the following misstatements that had no impact on net income which were previously identified and assessed as immaterial to the previously issued condensed financial statements: First, as part of its recordkeeping services, the Company funds certain plan sponsor expense accounts from which the plan can pay for qualified expenses. Management has determined that payment made to fund these plan sponsor expense accounts should be accounted for as customer payments. As such, the Company has restated its condensed consolidated statements of income to record the payment as a reduction of fee income rather than as general insurance expense. This misstatement impacts the unaudited condensed consolidated financial statements for the three and six months ended June 30, 2013. Second, management has reviewed its practices related to the accounting for certain fees paid by customers at the onset of an insurance contract and the related acquisition costs incurred by the Company on the sale of the insurance contract in the Company's executive benefits market. Management has concluded that the fees paid by the customers should be deferred as unearned revenue liability and the acquisition costs should be deferred as deferred acquisition costs asset in the condensed consolidated balance sheet. The Company has previously accounted for the fees paid by customers as a reduction of the deferred acquisition costs asset in the condensed consolidated balance sheet. This misstatement impacts the unaudited condensed consolidated financial statements as of June 30, 2013. Items Amended in This Amendment For the convenience of the reader, this Amendment sets forth the Original Filing, in its entirety, as modified and superseded where necessary to reflect the restatement. The following items in the Original Filing have been amended as a result of, and to reflect, the restatement: Part I Item 1. Interim Financial Statements; Part I Item 2. Management's Discussion and Analysis of Financial Condition and Results of Operations; Part I Item 4. Controls and Procedures; and Part II Item 6. Exhibits In accordance with applicable SEC rules, this Amendment includes new certifications required under the Securities and Exchange Act of 1934, as amended (Exchange Act), dated as of the filing date of this Amendment. All other information contained in the Company's Original Filing remains unchanged. The Company has not updated items in this Amendment to reflect events occurring after the Original Filing date, other than those associated with the restatement of the Company's financial statements. Without limitation to the foregoing, except as noted above, this Amendment does not purport to update Management's Discussion and Analysis of Financial Condition and Results of Operations contained in the Original Filing or any information, uncertainties, transactions, risks, events or trends occurring, or known to management. For updated information about the Company, refer to the Company's most recent filings with the SEC. Those filings contain important information regarding events, developments and updates to certain expectations of the Company that have occurred since the Original Filing.
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		7,032,000
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	Q2