Income Taxes (Details 2) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Assets
Accrued employee benefits	$ 8,860	$ 8,002
Goodwill and intangible assets		2,196
Allowance for doubtful accounts	170	476
Net operating loss carryforwards	758	987
Contract termination charge	180	714
Stock-based compensation	1,631	1,298
Deferred income	3,944	4,273
Deferred rent	372	196
Helicopter sale-leaseback	134	204
Acquisition costs	93
Other	119	120
Total	16,261	18,466
Liabilities
Goodwill and intangible assets	(1,649)
Appreciation on annuity contracts	(2,081)	(1,933)
Extinguishment of senior notes	(1,047)	(1,047)
Property, plant and equipment	(8,771)	(9,408)
Prepaid insurance	(452)	(344)
Other	(77)	(62)
Total	(14,077)	(12,794)
Valuation allowance	(411)	(480)
Deferred tax asset, net	1,773	5,192
Current asset, net	1,062	1,825
Noncurrent asset (liability), net	$ 711	$ 3,367