Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Allowance for doubtful accounts	$ 2,404	$ 3,019
Accumulated depreciation	360,513	319,769
Accumulated amortization	34,464	29,515
Accounts Payable	338,720	273,666
Due to Related Parties	9,030	5,033
Accrued Liabilities	84,703	85,047
Other Liabilities, Current	$ 11,510	$ 13,281
Common stock, $0.01 par value	$ 0.01	$ 0.01
Common stock shares authorized	100,000	100,000
Common stock shares issued	53,790	44,863
Treasury stock shares	977	931
Variable Interest Entity, Primary Beneficiary [Member]
Accounts Payable	$ 310,685	$ 243,548
Due to Related Parties	8,952	5,033
Accrued Liabilities	23,030	22,240
Other Liabilities, Current	$ 3,609	$ 4,246