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Investment in Unconsolidated Affiliate - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Sep. 30, 2017
Schedule of Equity Method Investments [Line Items]
Equity in earnings of joint venture		$ 7,939	$ 0	$ 0
Organic Valley Fresh Joint Venture
Schedule of Equity Method Investments [Line Items]
Ownership interest (as a percent)					50.00%
Payments to acquire equity method investments	$ 2,000
Distributions from joint venture		2,800
Equity in earnings of joint venture		(7,900)	$ 0
Corporate Joint Venture \| Organic Valley Fresh Joint Venture
Schedule of Equity Method Investments [Line Items]
Purchases from joint venture		$ 88,700