Computation of Basic and Diluted Earnings Per Share (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Earnings Per Share [Abstract]
Net income attributable to Wabtec shareholders	$ 90,155		$ 73,943		$ 258,994		$ 218,194
Less: dividends declared - common shares and non-vested restricted stock	(5,780)		(4,003)		(13,471)		(8,799)
Undistributed earnings	84,375		69,940		245,523		209,395
Percentage allocated to common shareholders	99.60%	[1]	99.60%	[1]	99.60%	[2]	99.50%	[2]
Undistributed earnings allocated to common shareholders	84,038		69,660		244,541		208,348
Add: dividends declared - common shares	5,759		3,986		13,415		8,757
Numerator for basic and diluted earnings per common share	$ 89,797		$ 73,646		$ 257,956		$ 217,105
Denominator for basic earnings per common share - weighted average shares	95,935		95,848		95,745		95,383
Assumed conversion of dilutive stock-based compensation plans	1,069		1,326		1,089		1,371
Denominator for diluted earnings per common share - adjusted weighted average shares and assumed conversion	97,004		97,174		96,834		96,754
Basic	$ 0.94		$ 0.77		$ 2.69		$ 2.28
Diluted earnings per share, As reported	$ 0.93		$ 0.76		$ 2.67		$ 2.25

[1] (1) Basic weighted-average common shares outstanding 95,935 95,848 Basic weighted-average common shares outstanding and non-vested restricted stock expected to vest 96,285 96,273 Percentage allocated to common shareholders 99.6% 99.6%

[2] (1) Basic weighted-average common shares outstanding 95,745 95,383 Basic weighted-average common shares outstanding and non-vested restricted stock expected to vest 96,146 95,850 Percentage allocated to common shareholders 99.6% 99.5%