Unearned Revenue

3 Months Ended

Mar. 31, 2019

Deferred Revenue Disclosure [Abstract]

Unearned Revenue

6.  Unearned Revenue

The following tables present our unearned revenue as of the respective periods (in thousands):

March 31, 2019

	Transportation		Water		Specialty		Total
California	$	402,482	$	7,314	$	66,089	$	475,885
Northwest		344,414		1,759		71,878		418,051
Heavy Civil		1,311,518		17,173		—		1,328,691
Federal		19		—		137,592		137,611
Midwest		128,867		143		180,449		309,459
Water and Mineral Services		—		193,914		—		193,914
Total	$	2,187,300	$	220,303	$	456,008	$	2,863,611

December 31, 2018

	Transportation		Water		Specialty		Total
California	$	314,261	$	6,163	$	57,820	$	378,244
Northwest		319,589		786		81,951		402,326
Heavy Civil		1,473,455		21,951		—		1,495,387
Federal		—		—		130,644		130,663
Midwest		78,004		211		203,601		281,816
Water and Mineral Services		—		189,597		—		189,597
Total	$	2,185,309	$	218,708	$	474,016	$	2,878,033

March 31, 2018

	Transportation		Water		Specialty		Total
California	$	305,234	$	26,902	$	49,892	$	382,028
Northwest		313,537		1,537		47,151		362,225
Heavy Civil		2,074,536		37,786		—		2,112,322
Federal		160		—		175,288		175,448
Midwest		80,054		1,543		318,049		399,646
Water and Mineral Services		—		16,912		—		16,912
Total	$	2,773,521	$	84,680	$	590,380	$	3,448,581