Securities Available for Sale

The amortized cost, gross unrealized gains and losses, and fair value of securities available for sale as of June 30, 2018 and December 31, 2017, were as follows:



June 30, 2018	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Asset-backed senior securities related to Company-sponsored securitizations ⁽¹⁾	$	65,044	$	57	$	(114	)	$	64,987
Asset-backed subordinated residual certificates related to Company-sponsored securitizations and CLUB Certificate transactions ⁽¹⁾	29,127		56		(456		)	28,727
Corporate debt securities	17,747		3		(4		)	17,746
Certificates of deposit	15,796		—		—			15,796
Asset-backed securities	13,077		—		(2		)	13,075
Commercial paper	9,473		—		—			9,473
Total securities available for sale	$	150,264	$	116	$	(576	)	$	149,804


December 31, 2017	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Asset-backed senior securities related to Company-sponsored securitizations ⁽¹⁾	$	36,953	$	73	$	(6	)	$	37,020
Certificates of deposit	24,758		—		—			24,758
Corporate debt securities	16,268		1		(11		)	16,258
Asset-backed securities	14,843		1		(1		)	14,843
Commercial paper	14,665		—		—			14,665
Asset-backed subordinated residual certificates related to Company-sponsored securitizations and CLUB Certificate transactions ⁽¹⁾	10,058		11		(40		)	10,029
Total securities available for sale	$	117,545	$	86	$	(58	)	$	117,573

⁽¹⁾

As of June 30, 2018 and December 31, 2017, approximately $92.0 million and $45.3 million, respectively, of the asset-backed securities related to Company-sponsored securitizations and CLUB Certificate transactions at fair value are subject to restrictions on transfer pursuant to the Company's obligations as a “sponsor” under the U.S. Risk Retention Rules (as more fully described in “Part II. Other Information – Item 1A. Risk Factors – Risk retention rules and recent developments in our business may increase our compliance costs, impair our liquidity and otherwise adversely affect our operating results” in the Company’s Annual Report on Form 10-K).

The senior securities and the subordinated residual certificates related to Company-sponsored securitization transactions and the retained portion of any CLUB Certificates are accounted for as securities available for sale, as described in “Note 7. Securitizations and Variable Interest Entities.” The senior securities are valued using prices obtained from third-party pricing services (Level 2 of the fair value hierarchy), as described in the Company’s Annual Report on Form 10-K (“Note 2. Summary of Significant Accounting Policies”). The subordinated residual certificates and retained portions of the CLUB Certificates are valued using discounted cash flow models that incorporate contractual payment terms and estimated discount rates, credit losses, and prepayment rates (Level 3 of the fair value hierarchy).

A summary of securities available for sale with unrealized losses as of June 30, 2018 and December 31, 2017, aggregated by period of continuous unrealized loss, is as follows:



	Less than 12 months					12 months or longer				Total
June 30, 2018	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
Asset-backed securities related to Company-sponsored securitizations and CLUB Certificate transactions	$	75,235	$	(570	)	$	—	$	—	$	75,235	$	(570	)
Corporate debt securities	10,101		(4		)	—		—		10,101		(4		)
Asset-backed securities	3,673		(2		)	—		—		3,673		(2		)
Total securities with unrealized losses ⁽¹⁾	$	89,009	$	(576	)	$	—	$	—	$	89,009	$	(576	)


	Less than 12 months					12 months or longer				Total
December 31, 2017	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
Asset-backed securities related to Company-sponsored securitizations and CLUB Certificate transactions	$	26,534	$	(46	)	$	—	$	—	$	26,534	$	(46	)
Corporate debt securities	14,368		(11		)	—		—		14,368		(11		)
Asset-backed securities	4,401		(1		)	—		—		4,401		(1		)
Total securities with unrealized losses ⁽¹⁾	$	45,303	$	(58	)	$	—	$	—	$	45,303	$	(58	)


⁽¹⁾	The number of investment positions with unrealized losses at June 30, 2018 and December 31, 2017 totaled 43 and 24, respectively.

During the second quarter and first half of 2018, the Company recognized $0.8 million and $2.1 million, respectively, in other-than-temporary impairment charges on its subordinated residual certificates held as a result of its Company-sponsored securitizations and on the retained portions of any CLUB Certificates. There were no credit losses recognized into earnings for other-than-temporarily impaired securities held by the Company during the second quarter and first half of 2018 for which a portion of the impairment was previously recognized in other comprehensive income. During the second quarter and first half of 2017, the Company recognized no other-than-temporary impairment charges.

The contractual maturities of securities available for sale at June 30, 2018, were as follows:



	Within 1 year		After 1 year through 5 years		Total
Corporate debt securities	$	17,746	$	—	$	17,746
Certificates of deposit	$	15,796	$	—	$	15,796
Asset-backed securities	10,075		3,000		13,075
Commercial paper	9,473		—		9,473
Fair value	$	53,090	$	3,000	$	56,090
Asset-backed securities related to Company-sponsored securitizations and CLUB Certificate transactions					93,714
Total fair value	$	53,090	$	3,000	$	149,804
Total amortized cost	$	53,093	$	3,000	$	150,264

During the second quarter and first half of 2018, the Company and the Company’s Consumer Loan Underlying Bond Depositor LLC (Depositor) sold $496.6 million and $937.2 million, respectively, in asset-backed securities related to Company-sponsored securitizations and CLUB Certificate transactions. During the second quarter and first half of 2017, the Company sold $265.4 million in asset-backed securities related to the Company’s sponsored securitization transaction. There were no realized gains or losses related to such sales. For further information, see “Note 7. Securitizations and Variable Interest Entities.” Proceeds from other sales of securities available for sale during both the second quarter and first half of 2018 were $0.5 million resulting in an immaterial loss. There were no other sales of securities available for sale during the first half of 2017.