SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule Of Basic and Diluted Earnings (Loss) Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Accounting Policies [Abstract]
Net income (loss) attributable to Werner	$ (14,399)	$ 34,233	$ 112,382
Weighted average common shares outstanding (in shares)	60,607	62,450	63,374
Dilutive effect of stock-based awards (in shares)	0	212	344
Shares used in computing diluted earnings (loss) per share (in shares)	60,607	62,662	63,718
Basic earnings (loss) per share (in dollars per share)	$ (0.24)	$ 0.55	$ 1.77
Diluted earnings (loss) per share (in dollars per share)	$ (0.24)	$ 0.55	$ 1.76