Commitments and Contingencies - Additional Information (Detail) (USD $)	0 Months Ended	3 Months Ended			12 Months Ended			1 Months Ended	3 Months Ended
	Oct. 09, 2013	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Dec. 31, 2014 Customer	Dec. 31, 2013 Customer	Dec. 31, 2012 Customer	Apr. 30, 2014	Mar. 31, 2014	Jul. 31, 2014	Dec. 31, 2011	Apr. 21, 2010 mi
Loss Contingencies [Line Items]
Outstanding capital commitment		$ 800,000
Rent expense related to operating leases					162,500,000	112,800,000	92,300,000
Maximum guaranteed residual value			434,200,000		434,200,000
Provision for long-term contract receivable			49,900,000	52,500,000	102,460,000
Selling, general and administrative expenses					722,038,000	501,010,000	434,894,000
Number of customers representing ten percent or more of net position						2
Number of customers representing ten percent or more of consolidated revenues					0	0	0
Gross amount accrued for insurance claims			170,200,000		170,200,000	161,800,000
Long-term insurance claims			130,800,000		130,800,000	122,600,000
Related insurance recoveries/receivables			9,100,000		9,100,000	9,100,000
Related insurance recoveries/receivables included in prepaid expenses and other current assets			800,000		800,000	700,000
Related insurance recoveries/receivables included in other assets net			8,300,000		8,300,000	8,400,000
Letters of credit and bank guarantees under the credit facility			336,700,000		336,700,000
Total amount of outstanding performance bonds			2,800,000,000		2,800,000,000
Estimated cost to complete bonded projects			701,000,000		701,000,000
Multi-employer plan withdrawal obligation										39,600,000	32,600,000
Multi-employer plan withdrawal obligation, amount suggested by Plan which is different than amount recorded by company	6,900,000
Multi-employer plan withdrawal obligation complete withdrawal	4,800,000
Multi-employer plan withdrawal obligation accrued					3,100,000
Cash proceeds deposited in Escrow account	2,100,000
Customer One [Member]
Loss Contingencies [Line Items]
Percentage of net position						15.00%
Other Customer [Member]
Loss Contingencies [Line Items]
Percentage of net position						11.00%
Sunrise Powerlink Project [Member]
Loss Contingencies [Line Items]
Length of electrical transmission line to be constructed under contract												117
Long-term contract receivable						165,000,000
Claim for breach of contract					113,000,000
Counterclaim for alleged untimely performance and breach of contract					32,000,000
Contract receivable			65,000,000		65,000,000
Provision for long-term contract receivable			49,900,000	52,500,000	102,500,000
Alberta Power Line [Member]
Loss Contingencies [Line Items]
Length of electrical transmission line to be constructed under contract			500		500
Payment by 2017 [Member]
Loss Contingencies [Line Items]
Outstanding capital commitment					10,100,000
Fiber Optic Committed Capital [Member]
Loss Contingencies [Line Items]
Estimated committed capital remainder of current year			16,800,000		16,800,000
Vehicle Fleet Committed Capital [Member]
Loss Contingencies [Line Items]
Estimated committed capital remainder of current year			5,600,000		5,600,000
Minimum [Member]
Loss Contingencies [Line Items]
Multi-employer plan withdrawal obligation			40,100,000		40,100,000
Minimum [Member] | Sales Revenue, Net [Member] | Customer Concentration Risk [Member]
Loss Contingencies [Line Items]
Concentration risk percentage					10.00%	10.00%	10.00%
Minimum [Member] | Net Position [Member] | Customer Concentration Risk [Member]
Loss Contingencies [Line Items]
Concentration risk percentage					10.00%	10.00%
Maximum [Member]
Loss Contingencies [Line Items]
Multi-employer plan withdrawal obligation			55,400,000		55,400,000
National Gas Company of Trinidad and Tobago Arbitration [Member]
Loss Contingencies [Line Items]
Damages sought by Company in arbitration, value					16,500,000
Loss contingency, damages sought by customer in arbitration counterclaim, value					79,500,000
Arbitration damages liability									17,300,000
Interest payable on arbitration damages and related attorney fees payable									11,000,000
Amount of arbitration damages and attorneys fee paid								28,300,000
Written Off of accounts receivable									10,500,000
Selling, general and administrative expenses					38,800,000				38,800,000
Lorenzo Bentonv Telecom Network Specialists Inc [Member]
Loss Contingencies [Line Items]
Number of staffing Agency					29
Lorenzo Bentonv Telecom Network Specialists Inc [Member] | Class Damage [Member]
Loss Contingencies [Line Items]
Amount sought by plaintiff					16,000,000
Lorenzo Bentonv Telecom Network Specialists Inc [Member] | Attorney Fees [Member]
Loss Contingencies [Line Items]
Amount sought by plaintiff					$ 5,000,000