Fair Value Measurements (Schedule of Fair Value Measurements of Assets and Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Current	$ 972	$ 3,302
Noncurrent	675	211
Total gross fair value	1,647	3,513
Less: counterparty set-off	1,647	3,513
Total net fair value	0	0
Current	10,694	10,026
Noncurrent	281	3,637
Total gross fair value	10,975	13,663
Less: counterparty set-off	1,647	3,513
Total net fair value	9,328	10,150
Parent Company [Member]
Current	972	3,302
Noncurrent	675	211
Current	10,694	10,026
Noncurrent	$ 281	$ 3,637