Organization and Summary of Significant Accounting Policies - Additional Information (Details) - USD ($)	6 Months Ended
	Jun. 30, 2017	May 31, 2018	Apr. 30, 2018	Jan. 01, 2018	Dec. 31, 2017	Dec. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Restricted Cash	$ 9,000,000					$ 9,000,000
Accounting Standards Update 2017-07 [Member] | Cost of Sales [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement, Effect of Adoption, Quantification	2,000,000
Accounting Standards Update 2017-07 [Member] | Selling, General and Administrative Expenses [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement, Effect of Adoption, Quantification	$ 1,000,000
Accounting Standards Update 2016-01 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Impact on retained earnings				$ 2,000,000
Accounting Standards Update 2014-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Impact on retained earnings					$ 0
ARGENTINA
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative Inflation Rate		109.00%
Central Bank Interest Rate		40.00%	30.00%