Acquisitions - Additional Information (Detail) shares in Millions					3 Months Ended	4 Months Ended
	Mar. 21, 2017 USD ($)	Mar. 06, 2017 USD ($)	Feb. 03, 2017 USD ($)	Nov. 30, 2016 USD ($) employee country	Mar. 31, 2017 USD ($)	Mar. 21, 2017 USD ($) shares	Mar. 14, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 14, 2016 USD ($)	Nov. 30, 2016 € / shares	Nov. 17, 2016 USD ($)	Aug. 01, 2016 USD ($)	May 05, 2016 USD ($)
Business Acquisition [Line Items]
Escrow deposits					$ 0			$ 744,748,000
Adjustment to preliminary purchase allocation					50,947,000
Goodwill					2,188,503,000			2,078,765,000
Acquired indefinite-lived intangible assets					681,600,000
Trade Names
Business Acquisition [Line Items]
Acquired indefinite-lived intangible assets					357,100,000
Customer Relationships
Business Acquisition [Line Items]
Acquired indefinite-lived intangible assets					$ 317,800,000
Intangible assets, weighted average useful life (years)					20 years
Noncompete Agreements
Business Acquisition [Line Items]
Intangible assets, weighted average useful life (years)					5 years
Intellectual Property
Business Acquisition [Line Items]
Acquired indefinite-lived intangible assets					$ 5,000,000
Intangible assets, weighted average useful life (years)					20 years
Faiveley Transport
Business Acquisition [Line Items]
Annual sales of Faiveley				$ 1,200,000,000
Number of employees (more than) | employee				5,700
Number of countries Faiveley operates in | country				24
Purchase price per share (in euros per share) | € / shares										€ 100
Outstanding share capital acquired (as a percent)										51.00%
Percentage of voting interests in Faiveley (as a percent)	100.00%	22.00%	27.00%			100.00%				49.00%
Share conversion ratio										1.1538
Additional share capital acquired (as a percent)		21.00%	27.00%
Cash payment for acquisition	$ 17,500,000	$ 303,200,000	$ 411,800,000			$ 944,300,000
Equity issued in acquisition		$ 300,000	$ 25,200,000			$ 560,200,000
Cumulative share capital acquired (as a percent)	100.00%	99.00%	78.00%			100.00%
Cumulative voting rights acquired (as a percent)	100.00%	98.00%	76.00%			100.00%
Business combination, consideration transferred						$ 1,736,100,000
Equity issued in acquisition (in shares) | shares						6.6
Debt assumed in acquisition						$ 409,900,000
Cash acquired in acquisition						$ 178,300,000
Escrow deposits								$ 744,700,000
Acquisition of noncontrolling interest					$ 8,900,000
Adjustment to current liabilities acquired					28,900,000
Current liabilities					774,751,000
Adjustment to other noncurrent assets					17,000,000
Adjustment to preliminary purchase allocation					43,800,000
Accounts receivable					444,918,000
Accrued share based compensation acquired in acquisition					25,900,000
Revenue reported by acquired entity					274,700,000
Goodwill					1,232,143,000
Faiveley Transport | Minimum
Business Acquisition [Line Items]
Percentage of business acquisition consideration payable in cash (as a percent)										25.00%
Faiveley Transport | Maximum
Business Acquisition [Line Items]
Percentage of business acquisition consideration payable in cash (as a percent)										45.00%
Faiveley Transport | Restatement Adjustment | Fair Value of Receivables
Business Acquisition [Line Items]
Accounts receivable					2,800,000
Faiveley Transport | Restatement Adjustment | Fair Value of Current Liabilities
Business Acquisition [Line Items]
Current liabilities					27,900,000
Faiveley Transport | Restatement Adjustment | Fair Value of Assets Acquired and Liabilities Assumed
Business Acquisition [Line Items]
Current liabilities					64,300,000
Accounts receivable					64,300,000
Acquisitions other than Faiveley
Business Acquisition [Line Items]
Escrow deposits					$ 48,600,000
ATP
Business Acquisition [Line Items]
Other intangible assets							$ 34,800,000
Purchase price, net of cash acquired							65,212,000
Goodwill							35,146,000
Goodwill tax deduction							$ 0
Workhorse
Business Acquisition [Line Items]
Other intangible assets									$ 19,400,000
Purchase price, net of cash acquired									44,292,000
Goodwill									$ 24,838,000
Goodwill deductible for taxes (as a percent)									37.80%
Precision Turbo
Business Acquisition [Line Items]
Other intangible assets											$ 5,200,000
Purchase price, net of cash acquired											13,846,000
Goodwill											3,942,000
Goodwill tax deduction											$ 3,900,000
Unitrac
Business Acquisition [Line Items]
Other intangible assets													$ 1,230,000
Purchase price, net of cash acquired													14,378,000
Goodwill													1,388,000
Goodwill tax deduction													$ 1,400,000
Gerken
Business Acquisition [Line Items]
Other intangible assets												$ 30,560,000
Purchase price, net of cash acquired												62,847,000
Goodwill												17,470,000
Goodwill tax deduction												$ 0