Commitments (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Commitments [Line Items]
Capital expenditures committed, but not yet incurred	$ 1,820	$ 884
Operating Leases, Rent Expense, Sublease Rentals	1,077	1,802
Operating Leases, Rent Expense, Net	17,367	18,139	$ 17,077
Net carrying capital lease amount	$ 2,192	3,331
Minimum [Member]
Commitments [Line Items]
Operating lease fixed term	1 month
Maximum [Member]
Commitments [Line Items]
Operating lease fixed term	20 years
Computer Software and Equipment [Member]
Commitments [Line Items]
Net carrying capital lease amount	$ 1,948	3,099
Computer and Yard Equipment [Member]
Commitments [Line Items]
Net carrying capital lease amount	$ 2,192	$ 3,331
Computer and Yard Equipment [Member] | Minimum [Member]
Commitments [Line Items]
Capital lease fixed term	1 month
Computer and Yard Equipment [Member] | Maximum [Member]
Commitments [Line Items]
Capital lease fixed term	3 years