Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018
Numerator
Net income attributable to Wabtec shareholders	$ 104,235		$ 84,416		$ 99,763	$ 172,782
Less: dividends declared - common shares and non-vested restricted stock	(22,576)	$ (11,687)	(11,565)	$ (11,531)	(34,264)	(23,096)
Undistributed earnings	$ 81,659		$ 72,851		$ 65,499	$ 149,686
Percentage allocated to common shareholders (as a percent)	99.70%		99.70%		99.70%	99.70%
Undistributed earnings allocated to common shareholders	$ 81,414		$ 72,632		$ 65,303	$ 149,237
Add: dividends declared - common shares	22,508		11,531		34,154	23,027
Dividends declared - preferred shares	(422)		0		(422)	0
Numerator for basic earnings per common share	103,500		84,163		99,035	172,264
Dividends declared - preferred shares	422		0		422	0
Numerator for diluted earnings per common share	$ 103,922		$ 84,163		$ 99,457	$ 172,264
Denominator
Basic weighted average common shares outstanding (in shares)	177,348		95,992		149,553	95,867
Assumed conversion of preferred shares (in shares)	13,743		0		12,213	0
Assumed conversion of dilutive stock-based compensation plans (in shares)	362		583		389	604
Denominator for diluted earnings per common share - adjusted weighted average shares and assumed conversion (in shares)	191,453		96,575		162,155	96,471
Net income attributable to Wabtec shareholders per common share
Basic (in dollars per share)	$ 0.58		$ 0.88		$ 0.66	$ 1.80
Diluted (in dollars per share)	$ 0.54		$ 0.87		$ 0.61	$ 1.79
Basic weighted-average common shares outstanding and non-vested restricted stock expected to vest (in shares)	177,922		96,276		150,013	96,153