Investments in Unconsolidated Affiliates (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Assets:
Current assets	$ 57,492
Noncurrent assets	161,280
Total assets	218,772
Liabilities:
Current liabilities	44,366
Noncurrent liabilities	86,658
Total liabilities	131,024
Results of operations:
Revenue	146,972	168,893
Net loss	$ (5,693)	$ (1,102)