GRT Acquisition - Estimated Fair Values of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016	Dec. 01, 2016
Assets
Goodwill	$ 53,673	$ 52,705
GRT Acquisition
Assets
Cash			$ 8,091
Accounts receivable			2,844
Notes receivable			3,050
Inventory			7,983
Other current assets			981
Property, plant & equipment			46,712
Intangible assets			7,412
Other long-term assets			289
Goodwill			33,861
Liabilities
Accounts payable			(61,570)
Notes payable			(10,122)
Accrued liabilities			(2,866)
Long-term debt			(3,383)
Other long-term liabilities			(940)
Net assets and liabilities assumed			32,342
Noncontrolling shareholder interest			(18,323)
Cooper Tire & Rubber Company consideration			$ 14,019