Accounts and Notes Receivable (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Financing Receivables [Line Items]
Accounts receivable - unrelated parties	$ 137,165	[1]	$ 140,920	[1]
Notes receivable - unrelated parties	146,597	[2],[3]	128,068	[2],[3]
Total accounts and notes receivable- unrelated parties	283,762		268,988
Less: allowance for doubtful accounts- unrelated parties	(1,414)		(1,349)		(1,266)
Accounts and notes receivable- unrelated parties	282,348		267,639
Accounts and notes receivable - related parties	22,760		17,194
Accounts and notes receivable, net	$ 305,108		$ 284,833

[1] As of December 31, 2014, the Company has pledged $34.3 million of accounts receivable as security for its comprehensive credit facility with banks in China.

[2] Notes receivable represents accounts receivable in the form of bills of exchange whose acceptances and settlements are handled by banks.

[3] As of December 31, 2014, Henglong collateralized its notes receivable in an amount of RMB232.5 million (equivalent to approximately $38.0 million) as security for the credit facilities with banks in China and the Chinese government, including RMB201.8 million (equivalent to approximately $33.0 million) in favor of Industrial and Commercial Bank of China, Jingzhou Branch, “ICBC Jingzhou,” for the purpose of obtaining the Henglong Standby Letter of Credit (as defined in Note 13) which is used as security for the non-revolving credit facility in the amount of $30.0 million provided by Industrial and Commercial Bank of China (Macau) Limited, “ICBC Macau,” and RMB30.7 million (equivalent to approximately $5.0 million) in favor of the Chinese government as security for the low-interest government loan (See Note 13). As of December 31, 2013, Henglong collateralized its notes receivable in an amount of RMB196.3 million (equivalent to approximately $32.2 million) in favor of Industrial and Commercial Bank of China, Jingzhou Branch, “ICBC Jingzhou,” for the purpose of obtaining the Henglong Standby Letter of Credit (as defined in Note 13) which is used as security for the non-revolving credit facility in the amount of $30.0 million provided by Industrial and Commercial Bank of China (Macau) Limited, “ICBC Macau.”