Discontinued Operations - Assets and Liabilities (Details) - Discontinued Operations, Held-for-sale or Disposed of by Sale - South African Distribution Business and Zambian Operations - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total assets	$ 0	$ 0
Accrued and other liabilities	0	686
Total liabilities	0	686
Net assets	$ 0	$ (686)