(3) Revenue

Disaggregation of Revenue

The following tables disaggregate revenue by end market, customer type and contract type, which the Company believes best depict how the nature, amount, timing and uncertainty of its revenue and cash flows are affected by economic factors for the three months ended March 31, 2019 and 2018.



	Three Months Ended
	March 31,
(in thousands)	2019		2018
Civil segment revenue by end market:
Mass transit	$	146,250	$	150,126
Bridges		69,307		62,811
Highways		41,043		17,257
Tunneling		34,940		8,701
Other		41,954		24,219
Total Civil segment revenue	$	333,494	$	263,114



	Three Months Ended
	March 31,
(in thousands)	2019		2018
Building segment revenue by end market:
Commercial and industrial facilities	$	109,353	$	173,747
Health care facilities		80,227		75,081
Municipal and government		61,962		50,452
Hospitality and gaming		47,957		81,765
Education facilities		42,528		32,482
Mixed use		36,627		41,777
Mass transit		29,177		—
Other		25,635		34,937
Total Building segment revenue	$	433,466	$	490,241



	Three Months Ended
	March 31,
(in thousands)	2019		2018
Specialty Contractors segment revenue by end market:
Mass transit	$	81,394	$	75,182
Commercial and industrial facilities		44,023		39,339
Health care facilities		11,652		16,365
Education facilities		11,580		25,304
Multi-unit residential		11,389		23,089
Mixed use		10,669		47,857
Transportation		6,435		33,985
Other		14,385		13,680
Total Specialty Contractors segment revenue	$	191,527	$	274,801



	Three Months Ended March 31, 2019
					Specialty
(in thousands)	Civil		Building		Contractors		Total
Revenue by customer type:
State and local agencies	$	257,107	$	144,686	$	97,071	$	498,864
Federal agencies		23,158		40,151		7,769		71,078
Private owners		53,229		248,629		86,687		388,545
Total revenue	$	333,494	$	433,466	$	191,527	$	958,487



	Three Months Ended March 31, 2018
					Specialty
(in thousands)	Civil		Building		Contractors		Total
Revenue by customer type:
State and local agencies	$	226,351	$	115,986	$	106,320	$	448,657
Federal agencies		9,855		44,311		18,723		72,889
Private owners		26,908		329,944		149,758		506,610
Total revenue	$	263,114	$	490,241	$	274,801	$	1,028,156



	Three Months Ended March 31, 2019
					Specialty
(in thousands)	Civil		Building		Contractors		Total
Revenue by contract type:
Fixed price	$	242,867	$	114,359	$	155,264	$	512,490
Guaranteed maximum price		2,233		207,131		3,606		212,970
Unit price		84,878		5,228		19,003		109,109
Cost plus fee and other		3,516		106,748		13,654		123,918
Total revenue	$	333,494	$	433,466	$	191,527	$	958,487



	Three Months Ended March 31, 2018
					Specialty
(in thousands)	Civil		Building		Contractors		Total
Revenue by contract type:
Fixed price	$	183,904	$	79,001	$	247,424	$	510,329
Guaranteed maximum price		5,072		262,028		15,579		282,679
Unit price		68,754		8,816		6,658		84,228
Cost plus fee and other		5,384		140,396		5,140		150,920
Total revenue	$	263,114	$	490,241	$	274,801	$	1,028,156

Changes in Contract Estimates that Impact Revenue

Changes to the total estimated contract revenue or cost, either due to unexpected events or revisions to management’s initial estimates, for a given project are recognized in the period in which they are determined. Net revenue recognized during the three month periods ended March 31, 2019 and 2018 related to performance obligations satisfied (or partially satisfied) in prior periods was immaterial.

Remaining Performance Obligations

Remaining performance obligations represent the transaction price of firm orders for which work has not been performed and exclude unexercised contract options. As of March 31, 2019, the aggregate amounts of the transaction prices allocated to the remaining performance obligations of the Company’s construction contracts were $4.5 billion, $2.0 billion and $1.8 billion for the Civil, Building and Specialty Contractors segments, respectively. As of March 31, 2018, the aggregate amounts of the transaction prices allocated to the remaining performance obligations of the Company’s construction contracts were $4.5 billion, $2.2 billion and $1.8 billion for the Civil, Building and Specialty Contractors segments, respectively. The Company typically recognizes revenue on Civil segment projects over a period of three to five years, whereas for projects in the Building and Specialty Contractors segments, the Company typically recognizes revenue over a period of one to three years.