Earnings Per Share - Computation of Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Numerator
Net income attributable to Wabtec shareholders	$ 73,889	$ 94,163
Less: dividends declared - common shares and non-vested restricted stock	(9,572)	(7,355)
Undistributed earnings	$ 64,317	$ 86,808
Percentage allocated to common shareholders (as a percent)	99.70%	99.70%
Undistributed earnings allocated to common shareholders	$ 64,124	$ 86,548
Add: dividends declared - common shares	9,542	7,332
Numerator for basic and diluted earnings per common share	$ 73,666	$ 93,880
Denominator
Basic weighted average common shares outstanding (in shares)	95,243	91,258
Assumed conversion of dilutive stock-based compensation plans (in shares)	748	891
Denominator for diluted earnings per common share - adjusted weighted average shares and assumed conversion (in shares)	95,991	92,149
Net income attributable to Wabtec shareholders per common share
Basic (in dollars per share)	$ 0.77	$ 1.03
Diluted (in dollars per share)	$ 0.77	$ 1.02
Basic weighted-average common shares outstanding and non-vested restricted stock expected to vest (in shares)	95,544	91,543