RESTRICTED INVESTMENTS AND BOND COLLATERAL (Tables)

9 Months Ended

Sep. 30, 2013

Disclosure Restricted Investments and Bond Collateral [Abstract]

Components of restricted investments and bond collateral

The Company’s restricted investments and bond collateral consist of the following:

	September 30, 2013		December 31, 2012
	(In thousands)
Coal Segment:
WML debt reserve account	$	13,066	$	13,062
Reclamation bond collateral:
Kemmerer Mine	24,715		24,702
Absaloka Mine	14,583		14,507
Rosebud Mine	12,496		12,495
Beulah Mine	1,270		1,270
Power Segment:
Letter of credit account	5,996		5,990
Corporate Segment:
Postretirement medical benefit bonds	8,445		8,593
Workers’ compensation bonds	6,648		6,590
Total restricted investments and bond collateral	$	87,219	$	87,209

Carrying value and estimated fair value of restricted investments and bond collateral

The Company’s carrying value and estimated fair value of its restricted investments and bond collateral at September 30, 2013 are as follows:

	Carrying Value		Fair Value
	(In thousands)
Cash and cash equivalents	$	48,553	$	48,553
Time deposits	8,440		8,440
Held-to-maturity securities	30,226		30,196
	$	87,219	$	87,189

Amortized cost, gross unrealized holding gains and losses and fair value of held-to-maturity securities

The amortized cost, gross unrealized holding gains and fair value of held-to-maturity securities at September 30, 2013 is as follows (in thousands):

Amortized cost	$	30,226
Gross unrealized holding gains	331
Gross unrealized holding losses	(361		)
Fair value	$	30,196

Maturities of held-to-maturity securities

Maturities of held-to-maturity securities are as follows at September 30, 2013:

	Amortized Cost		Fair Value
	(In thousands)
Due within one year	$	605	$	609
Due in five years or less	16,900		17,069
Due after five years to ten years	6,780		6,755
Due in more than ten years	5,941		5,763
	$	30,226	$	30,196