Quarterly report pursuant to Section 13 or 15(d)

Segment Information - Summarized Financial Information (Detail)

v3.7.0.1
Segment Information - Summarized Financial Information (Detail) - USD ($)
$ in Thousands
3 Months Ended
Mar. 31, 2017
Mar. 31, 2016
Segment Reporting Information [Line Items]    
Revenues $ 2,178,170 $ 1,713,737
Operating income (loss) 75,074 37,294
Depreciation 42,693 41,170
Electric Power Infrastructure Services [Member]    
Segment Reporting Information [Line Items]    
Revenues 1,219,502 1,187,002
Operating income (loss) 99,672 87,324
Depreciation 22,086 22,945
Oil and Gas Infrastructure Services Segment [Member]    
Segment Reporting Information [Line Items]    
Revenues 958,668 526,735
Operating income (loss) 38,817 5,841
Depreciation 17,364 15,801
Corporate and Non-Allocated Costs [Member]    
Segment Reporting Information [Line Items]    
Operating income (loss) (63,415) (55,871)
Depreciation $ 3,243 $ 2,424