Common Stock and Share-Based Compensation - Narrative (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred stock authorized (shares)									1,000,000,000,000
Common stock authorized (shares)									250,000,000
Common stock, par value (USD per share)	$ 0.01								$ 0.01	$ 0.01
Dividends paid (USD per share)	$ 0.03	$ 0.09	$ 0.09	$ 0.09	$ 0.09	$ 0.09	$ 0.09	$ 0.09	$ 0
Cash dividends paid									$ 0	$ (27,405,000)	$ (32,737,000)
Shares available for issuance (shares)									8,500,000
Dean Foods Company Two Thousand Seven Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option awarded (shares)									1.67
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted during period (shares)									0	0	0
Total unrecognized stock option expense									$ 0
Cash received from stock option exercises									0	$ 0
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized stock option expense									$ 1,900,000
Unrecognized compensation expense expected to be recognized period									1 year 2 months 26 days
Restricted Stock Units (RSUs) \| Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period									3 years
Restricted Stock Units (RSUs) \| Non-Employee Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period									3 years
Restricted Stock \| Non-Employee Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fee value option to receive in restricted stock (as a percent)									150.00%
PSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period									3 years
Phantom Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period									3 years
Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock repurchased (shares)									121,960	46,393	115,618
Minimum \| PSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting amount (as a percent)									0.00%
Maximum \| PSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting amount (as a percent)									200.00%
2016 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum stock options grants (shares)									11,750,000
Vesting period one \| Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting amount (as a percent)									33.33%
Vesting period two \| Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting amount (as a percent)									33.33%
Vesting period three \| Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting amount (as a percent)									33.33%

DEAN FOODS CO 10-K