CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 4,203	$ 5,343
Accounts receivable, net of allowances of $568 and $605, respectively	280,018	283,008
Costs and estimated earnings in excess of billings on uncompleted contracts	87,356	78,260
Current portion of receivable for insurance claims in excess of deductibles	4,380	4,221
Refundable income taxes, net	0	391
Other current assets	7,565	8,513
Total current assets	383,522	379,736
Property and equipment, net of accumulated depreciation of $242,985 and $231,391, respectively	155,571	148,084
Goodwill	46,984	46,994
Intangible assets, net of accumulated amortization of $5,423 and $5,183, respectively	10,592	10,852
Receivable for insurance claims in excess of deductibles	14,466	14,295
Investment in joint ventures	908	168
Other assets	3,551	3,659
Total assets	615,594	603,788
Current liabilities:
Current portion of capital lease obligations	1,102	1,086
Accounts payable	98,804	110,383
Billings in excess of costs and estimated earnings on uncompleted contracts	48,407	28,919
Current portion of accrued self-insurance	13,016	13,138
Income taxes payable, net	1,857	0
Other current liabilities	43,536	35,038
Total current liabilities	206,722	188,564
Deferred income tax liabilities	13,818	13,452
Long-term debt	57,804	78,960
Accrued self-insurance	32,093	32,225
Capital lease obligations, net of current maturities	2,068	2,629
Other liabilities	464	919
Total liabilities	312,969	316,749
Commitments and contingencies
Stockholders' equity:
Preferred stock—$0.01 par value per share; 4,000,000 authorized shares; none issued and outstanding at June 30, 2018 and December 31, 2017	0	0
Common stock—$0.01 par value per share; 100,000,000 authorized shares; 16,565,333 and 16,464,757 shares issued and outstanding at June 30, 2018 and December 31, 2017, respectively	165	163
Additional paid-in capital	146,610	143,934
Accumulated other comprehensive loss	(300)	(299)
Retained earnings	156,150	143,241
Total stockholders' equity	302,625	287,039
Total liabilities and stockholders' equity	$ 615,594	$ 603,788

Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

Name:	us-gaap_AccountsPayableCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130549-203045

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(3))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682