Derivative Financial Instruments and Fair Value Measurements - Carrying Value and Fair Value of Senior Notes and Subsidiary Senior Notes (Details) - Dean Foods Company - Dean Foods Company senior notes due 2023 - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Amount Outstanding	$ 700,000	$ 700,000
Fair Value	$ 672,000	$ 698,250