Earnings Per Share - Computation of Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Earnings Per Share [Abstract]
Net income attributable to Wabtec shareholders	$ 90,485	$ 101,504	$ 184,648	$ 197,668
Less: dividends declared - common shares and non-vested restricted stock	(7,209)	(5,799)	(14,565)	(11,580)
Undistributed earnings	$ 83,276	$ 95,705	$ 170,083	$ 186,088
Percentage allocated to common shareholders	99.70%	99.70%	99.70%	99.60%
Undistributed earnings allocated to common shareholders	$ 83,026	$ 95,418	$ 169,573	$ 185,344
Add: dividends declared - common shares	7,189	5,782	14,520	11,539
Numerator for basic and diluted earnings per common share	$ 90,215	$ 101,200	$ 184,093	$ 196,883
Basic weighted average common shares outstanding (in shares)	89,846	96,338	90,832	96,066
Assumed conversion of dilutive stock-based compensation plans (in shares)	713	1,097	796	1,046
Denominator for diluted earnings per common share - adjusted weighted average shares and assumed conversion (in shares)	90,559	97,435	91,628	97,112
Basic earnings per share (in dollars per share)	$ 1.00	$ 1.05	$ 2.03	$ 2.05
Diluted earnings per share, as reported (in dollars per share)	$ 1.00	$ 1.04	$ 2.02	$ 2.03
Basic weighted-average common shares outstanding and non-vested restricted stock expected to vest (in shares)	90,101	96,620	91,111	96,406