Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Fixed maturities - available for sale, amortized cost	$ 5,235,523	$ 5,116,600
Equity securities - available for sale, cost	15	15
Other invested assets, cost	435,010cik0000914748_OtherInvestedAssetsAtCost	385,776cik0000914748_OtherInvestedAssetsAtCost
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	3,000us-gaap_CommonStockSharesAuthorized	3,000us-gaap_CommonStockSharesAuthorized
Common stock, shares issued	1,000us-gaap_CommonStockSharesIssued	1,000us-gaap_CommonStockSharesIssued
Common stock, shares outstanding	1,000us-gaap_CommonStockSharesOutstanding	1,000us-gaap_CommonStockSharesOutstanding
Accumulated other comprehensive income (loss), deferred income tax expense (benefit)	$ 2,434us-gaap_OtherComprehensiveIncomeLossTax	$ 47,195us-gaap_OtherComprehensiveIncomeLossTax
Long Term Subordinated Debt [Member]
Debt instrument, stated interest rate	6.60%	6.60%
Debt instrument, maturity date	May 01, 2067	May 01, 2067
Senior Notes 4.868% [Member] \| Senior Notes [Member]
Debt instrument, stated interest rate	4.868%
Debt instrument, maturity date	Jun. 01, 2044
Senior Notes 5.4% [Member] \| Senior Notes [Member]
Debt instrument, stated interest rate		5.40%
Debt instrument, maturity date		Oct. 15, 2014

Other Invested Assets At Cost

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This item represents the cost of equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments for other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

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Amount of available-for-sale debt securities at cost, net of adjustments, which include, but are not limited to, accretion, amortization, collection of cash, previous other-than-temporary impairments (OTTI) recognized in earnings (less any cumulative-effect adjustments, as defined) and fair value hedge accounting adjustments.

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Face amount or stated value per share of common stock.

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Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

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Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

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Amount of tax expense (benefit) allocated to other comprehensive income (loss).

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