(5) Other Long-Term Assets and Other Income (Detail) - Other Long-Term Assets (Assets [Member], USD $) In Thousands, unless otherwise specified	Jun. 30, 2012		Dec. 31, 2011
Assets [Member]
Other assets:
Oil and gas properties, net	$ 334		$ 336
Advance coal royalties	3,129		3,205
Deferred financing costs, net	134		295
Marketable equity securities available for sale at fair value (restricted)*	3,581	[1]	2,326	[1]
Miscellaneous	1,771		132
	$ 8,949		$ 6,294

[1] *Held by Sunrise Indemnity, Inc., our wholly-owned captive insurance company.