Income Taxes (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Current tax provision (benefit):
State	$ 60	$ 918	$ 680
Total current	60	918	680
Deferred tax provision:
State	885
Total deferred	885
Provision for income taxes	945	918	680
Deferred tax liabilities:
Property, plant and equipment	(885)
Total deferred tax liabilities	(885)
Net deferred tax liabilities	(885)
Reconciliation of the beginning and ending amount of unrecognized tax benefits
Additions based on tax positions related to current year	96
Additions based on tax positions related to prior years	447
Ending balance	$ 543