Note 4. Investments

The Company accounts for its investments in accordance with Topic 320, Investments – Debt and Equity Securities. Management determines the appropriate classification of its investments in debt securities at the time of purchase and re-evaluates such determination on a quarterly basis. As of March 31, 2012, all of the Company's investments were classified as held to maturity, as the Company has the positive intent and ability to hold these securities to maturity. Held to maturity securities are carried at amortized cost. The amortized cost of debt securities is adjusted using the effective interest rate method for amortization of premiums and accretion of discounts. Such amortization and accretion is reported in other (income) expenses in the Company's consolidated statements of operations. These investments will be used to reimburse the insurance claim losses paid by the Company's captive insurance companies, Red Rock Risk Retention Group, Inc., ("Red Rock") and Mohave Transportation Insurance Company ("Mohave"), and are restricted by insurance regulations. The following table presents the cost or amortized cost, gross unrealized gains and losses, and estimated fair value of the Company's fixed maturity securities at March 31, 2012 (in thousands):


	March 31, 2012
	Cost or		Gross Unrealized				Estimated
	Amortized				Temporary		Fair
	Cost		Gains		Losses		Value
Fixed Maturity Securities-restricted:
Foreign corporate securities	$	2,022	$	—	$	27	$	1,995
U.S. corporate securities		9,064		4		6		9,062

Total fixed maturity securities-restricted	$	11,086	$	4	$	33	$	11,057

As of March 31, 2012, the contractual maturities of the fixed maturity securities were one year or less. As of March 31, 2012, the Company held five securities with unrealized losses for less than 12 months.

The Company periodically evaluates fixed maturity securities for impairment. The assessment of whether impairments have occurred is based on management's case-by-case evaluation of the underlying reasons for the decline in estimated fair value.

The Company accounts for other-than-temporary impairments of debt securities using the provisions of Topic 320 related to the recognition of other-than-temporary impairments of debt securities. This guidance requires the Company to evaluate whether it intends to sell an impaired debt security or whether it is more likely than not that it will be required to sell an impaired debt security before recovery of the amortized cost basis. If either of these criteria are met, an impairment equal to the difference between the debt security's amortized cost and its estimated fair value is recognized in earnings.

For impaired debt securities that do not meet this criteria, the Company determines if a credit loss exists with respect to the impaired security. If a credit loss exists, the credit loss component of the impairment (i.e., the difference between the security's amortized cost and the present value of projected future cash flows expected to be collected) is recognized in earnings and the remaining portion of the impairment is recognized as a component of accumulated OCI. The Company did not recognize any impairment losses for the three months ended March 31, 2012.