EARNINGS PER SHARE - Computation of Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Earnings Per Share [Abstract]
Net income attributable to Wabtec shareholders	$ 37,811	$ 82,428	$ 90,485	$ 94,163	$ 101,779	$ 99,181	$ 101,504	$ 96,164	$ 304,887	$ 398,628	$ 351,680
Less: dividends declared - common shares and non-vested restricted stock									(32,430)	(26,963)	(19,246)
Undistributed earnings									$ 272,457	$ 371,665	$ 332,434
Percentage allocated to common shareholders									99.70%	99.70%	99.60%
Undistributed earnings allocated to common shareholders									$ 271,640	$ 370,550	$ 331,104
Dividends declared - common shares									32,333	26,875	19,167
Numerator for basic and diluted earnings per common share									$ 303,973	$ 397,425	$ 350,271
Denominator for basic earnings per common share - weighted average shares (in shares)									90,359	96,074	95,781
Assumed conversion of dilutive stock-based compensation plans (in shares)									782	932	1,104
Denominator for diluted earnings per common shares - adjusted weighted average shares and assumed conversion (in shares)									91,141	97,006	96,885
Net income attributable to Wabtec shareholders (in dollars per share)	$ 0.42	$ 0.92	$ 1.00	$ 1.03	$ 1.06	$ 1.03	$ 1.05	$ 1.00	$ 3.37	$ 4.14	$ 3.66
Net income attributable to Wabtec shareholders (in dollars per share)	$ 0.42	$ 0.91	$ 1.00	$ 1.02	$ 1.05	$ 1.02	$ 1.04	$ 0.99	$ 3.34	$ 4.10	$ 3.62
Basic weighted-average common shares outstanding and non-vested restricted stock expected to vest									90,627	96,388	96,175