Earnings Per Share - Diluted (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Earnings Per Share [Abstract]
Net income attributable to Quaker Chemical Corporation	$ 10,486	$ 13,358	$ 32,972	$ 33,799
Less: income allocated to participating securities	(99)	(222)	(384)	(604)
Net income available to common shareholders	$ 10,387	$ 13,136	$ 32,588	$ 33,195
Basic weighted average common shares outstanding	12,937,417	12,621,459	12,840,029	11,989,748
Effect of dilutive securities	33,892	148,919	70,265	166,787
Diluted weighted average common shares outstanding	12,971,309	12,770,378	12,910,294	12,156,535
Diluted earnings per common share	$ 0.80	$ 1.03	$ 2.52	$ 2.73