CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (327,358)	$ 61,588	$ 119,929
Other comprehensive income (loss):
Cumulative translation adjustment	0	0	(2,257)
Defined benefit pension and other postretirement benefit plans, net of tax:
Prior service costs arising during the period	0	(819)	0
Net gain (loss) arising during the period	(9,971)	4,958	(8,452)
Less: amortization of prior service cost included in net periodic benefit cost	6,621	7,084	6,879
Other comprehensive income (loss)	(3,350)	11,223	(3,830)
Comprehensive income (loss)	(330,708)	72,811	116,099
Comprehensive loss attributable to non-controlling interest	458	0	0
Comprehensive income (loss) attributable to Dean Foods Company	$ (330,250)	$ 72,811	$ 116,099