Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Restricted Cash) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Restricted assets [Line Items]
Document Fiscal Year Focus	2014
Restricted assets	$ 1,937	$ 1,819
Deposits for payment of casualty & health insurance claims [Member]
Restricted assets [Line Items]
Restricted assets	785	1,306
Other deposits [Member]
Restricted assets [Line Items]
Restricted assets	$ 1,152	$ 513