Comfort Systems USA (FIX) 10-Q 26 Oct 17 2017 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2017	Oct. 19, 2017
Document and Entity Information
Entity Registrant Name	COMFORT SYSTEMS USA INC
Entity Central Index Key	1,035,983
Document Type	10-Q
Document Period End Date	Sep. 30, 2017
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		37,134,226
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q3

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
CURRENT ASSETS:
Cash and cash equivalents	$ 29,496	$ 32,074
Accounts receivable, less allowance for doubtful accounts of $4,328 and $4,288, respectively	390,497	318,837
Other receivables	13,651	20,363
Inventories	10,778	9,208
Prepaid expenses and other	11,622	6,106
Costs and estimated earnings in excess of billings	39,333	29,369
Total current assets	495,377	415,957
PROPERTY AND EQUIPMENT, NET	74,883	68,195
GOODWILL	203,771	149,208
IDENTIFIABLE INTANGIBLE ASSETS, NET	78,527	42,435
DEFERRED INCOME TAX ASSETS	27,282	27,170
OTHER NONCURRENT ASSETS	4,747	5,938
Total assets	884,587	708,903
CURRENT LIABILITIES:
Current maturities of long-term debt	618	600
Current maturities of long-term capital lease obligations	90	163
Accounts payable	122,203	103,440
Accrued compensation and benefits	68,294	61,712
Billings in excess of costs and estimated earnings	103,049	83,985
Accrued self-insurance	32,774	33,520
Other current liabilities	46,774	34,261
Total current liabilities	373,802	317,681
LONG-TERM DEBT	80,951	1,955
LONG-TERM CAPITAL LEASE OBLIGATIONS	33	93
DEFERRED INCOME TAX LIABILITIES	2,289	2,289
OTHER LONG-TERM LIABILITIES	15,583	10,252
Total liabilities	472,658	332,270
COMMITMENTS AND CONTINGENCIES
STOCKHOLDERS' EQUITY:
Preferred stock, $.01 par, 5,000,000 shares authorized, none issued and outstanding
Common stock, $.01 par, 102,969,912 shares authorized, 41,123,365 and 41,123,365 shares issued, respectively	411	411
Treasury stock, at cost, 3,989,139 and 3,914,251 shares, respectively	(64,312)	(57,387)
Additional paid-in capital	312,312	309,625
Retained earnings	163,518	123,984
Total stockholders’ equity	411,929	376,633
Total liabilities and stockholders' equity	$ 884,587	$ 708,903

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
CONSOLIDATED BALANCE SHEETS
Accounts receivable, allowance for doubtful accounts (in dollars)	$ 4,328	$ 4,288
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	102,969,912	102,969,912
Common stock, shares issued	41,123,365	41,123,365
Treasury stock, shares	3,989,139	3,914,251

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
CONSOLIDATED STATEMENTS OF OPERATIONS
REVENUE	$ 480,851	$ 428,760	$ 1,326,850	$ 1,242,240
COST OF SERVICES	379,993	335,944	1,054,300	986,496
Gross profit	100,858	92,816	272,550	255,744
SELLING, GENERAL AND ADMINISTRATIVE EXPENSES	66,707	61,032	196,553	180,245
GOODWILL IMPAIRMENT			1,105
GAIN ON SALE OF ASSETS	(184)	(166)	(464)	(523)
Operating income	34,335	31,950	75,356	76,022
OTHER INCOME (EXPENSE):
Interest income	16	3	55	6
Interest expense	(961)	(563)	(2,392)	(1,870)
Changes in the fair value of contingent earn-out obligations	2,469	804	1,845	468
Other	10	80	57	455
Other income (expense)	1,534	324	(435)	(941)
INCOME BEFORE INCOME TAXES	35,869	32,274	74,921	75,081
INCOME TAX EXPENSE	13,585	11,803	27,188	27,052
NET INCOME	$ 22,284	$ 20,471	$ 47,733	$ 48,029
Basic-
Net income (in dollars per share)	$ 0.60	$ 0.55	$ 1.28	$ 1.28
Diluted-
Net income (in dollars per share)	$ 0.59	$ 0.54	$ 1.27	$ 1.27
SHARES USED IN COMPUTING INCOME PER SHARE:
Basic (in shares)	37,232	37,360	37,259	37,380
Diluted (in shares)	37,626	37,821	37,684	37,854
DIVIDENDS PER SHARE (in dollars per share)	$ 0.075	$ 0.070	$ 0.220	$ 0.205

CONSOLIDATED STATEMENTS OF STOC

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Common Stock	Treasury Stock	Additional Paid-In Capital	Retained Earnings	Non-Controlling Interests	Total
BALANCE at Dec. 31, 2015	$ 411	$ (46,845)	$ 323,765	$ 69,390	$ 18,284	$ 365,005
BALANCE (in shares) at Dec. 31, 2015	41,123,365
BALANCE (in shares) at Dec. 31, 2015		(3,696,781)
Increase (Decrease) in Stockholders' Equity
Net income						$ 48,029
BALANCE (in shares) at Sep. 30, 2016						37,230,000
BALANCE at Dec. 31, 2015	$ 411	$ (46,845)	323,765	69,390	18,284	$ 365,005
BALANCE (in shares) at Dec. 31, 2015	41,123,365
BALANCE (in shares) at Dec. 31, 2015		(3,696,781)
Increase (Decrease) in Stockholders' Equity
Net income				64,896		64,896
Issuance of Stock:
Issuance of shares for options exercised		$ 1,568	10			1,578
Issuance of shares for options exercised (in shares)		111,761
Issuance of restricted stock & performance stock		$ 2,282	(306)			1,976
Issuance of restricted stock & performance stock (in shares)		172,727
Shares received in lieu of tax withholding payment on vested restricted stock		$ (1,304)				(1,304)
Shares received in lieu of tax withholding payment on vested restricted stock (in shares)		(41,788)
Stock-based compensation			3,502			3,502
Dividends				(10,264)		(10,264)
Share repurchase		$ (13,088)				(13,088)
Share repurchase (in shares)		(460,170)
Acquisition of noncontrolling interests			(17,346)		$ (18,284)	(35,630)
Stockholders' Equity Attributable to Parent, Ending Balance at Dec. 31, 2016	$ 411	$ (57,387)	309,625	123,984		$ 376,633
BALANCE (in shares) at Dec. 31, 2016	41,123,365
BALANCE (in shares) at Dec. 31, 2016		(3,914,251)				3,914,251
Increase (Decrease) in Stockholders' Equity
Cumulative effect of change in accounting principle (unaudited)				(38)		$ (38)
Net income				47,733		47,733
Issuance of Stock:
Issuance of shares for options exercised		$ 1,366	(70)			1,296
Issuance of shares for options exercised (in shares)		90,498
Issuance of restricted stock & performance stock		$ 2,037	(421)			1,616
Issuance of restricted stock & performance stock (in shares)		134,646
Shares received in lieu of tax withholding payment on vested restricted stock		$ (1,419)				(1,419)
Shares received in lieu of tax withholding payment on vested restricted stock (in shares)		(39,335)
Stock-based compensation			3,178			3,178
Dividends				(8,199)		(8,199)
Share repurchase		$ (8,909)				(8,909)
Share repurchase (in shares)		(260,697)
Stockholders' Equity Attributable to Parent, Ending Balance at Sep. 30, 2017	$ 411	$ (64,312)	$ 312,312	$ 163,518		$ 411,929
BALANCE (in shares) at Sep. 30, 2017	41,123,365					37,134,000
BALANCE (in shares) at Sep. 30, 2017		(3,989,139)				3,989,139

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 47,733	$ 48,029
Adjustments to reconcile net income to net cash provided by operating activities
Amortization of identifiable intangible assets	12,622	6,227
Depreciation expense	14,714	13,444
Goodwill impairment	1,105
Bad debt expense (benefit)	29	(177)
Deferred tax expense (benefit)	(112)	(606)
Amortization of debt financing costs	282	273
Gain on sale of assets	(464)	(523)
Changes in the fair value of contingent earn-out obligations	(1,845)	(468)
Stock-based compensation	4,317	3,868
(Increase) decrease in-
Receivables, net	(38,051)	(4,301)
Inventories	(1,059)	(298)
Prepaid expenses and other current assets	(608)	(3,648)
Costs and estimated earnings in excess of billings	(7,348)	(3,726)
Other noncurrent assets	913	(128)
Increase (decrease) in-
Accounts payable and accrued liabilities	22,595	1,628
Billings in excess of costs and estimated earnings	10,309	(10,928)
Other long-term liabilities	560	1,088
Net cash provided by operating activities	65,692	49,754
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment	(16,830)	(17,257)
Proceeds from sales of property and equipment	784	847
Cash paid for acquisitions, net of cash acquired	(94,860)	(58,510)
Net cash used in investing activities	(110,906)	(74,920)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from revolving line of credit	140,000	144,000
Payments on revolving line of credit	(74,000)	(129,000)
Payments on other debt	(798)	(567)
Payments on capital lease obligations	(133)	(194)
Debt financing costs		(789)
Payments of dividends to stockholders	(8,199)	(7,663)
Share repurchase	(8,909)	(10,977)
Shares received in lieu of tax withholding	(1,419)	(1,304)
Proceeds from exercise of options	1,296	733
Deferred acquisition payments	(2,802)
Payments for contingent consideration arrangements	(2,400)	(200)
Net cash provided by (used in) financing activities	42,636	(5,961)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	(2,578)	(31,127)
CASH AND CASH EQUIVALENTS, beginning of period	32,074	56,464
CASH AND CASH EQUIVALENTS, end of period	$ 29,496	$ 25,337

Business and Organization

Business and Organization	9 Months Ended
	Sep. 30, 2017
Business and Organization
Business and Organization	1. Business and Organization Comfort Systems USA, Inc., a Delaware corporation, provides comprehensive mechanical contracting services, which principally includes heating, ventilation and air conditioning (“HVAC”), plumbing, piping and controls, as well as off-site construction, electrical, monitoring and fire protection. We install, maintain, repair and replace products and systems throughout the United States. Approximately 37% of our consolidated 2017 revenue is attributable to installation of systems in newly constructed facilities, with the remaining 63% attributable to maintenance, repair and replacement services. Our consolidated 2017 revenue was derived from the following service activities, all of which are in the mechanical services industry, the single industry segment we serve: Revenue Service Activity $ in thousands % HVAC and Plumbing $ 1,207,434 91 % Building Automation Control Systems 66,343 5 % Other 53,073 4 % Total $ 1,326,850 100 %

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2017
Summary of Significant Accounting Policies
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation These interim statements should be read in conjunction with the historical Consolidated Financial Statements and related notes of Comfort Systems included in the Annual Report on Form 10-K as filed with the Securities and Exchange Commission (“SEC”) for the year ended December 31, 2016 (the “Form 10-K”). The accompanying unaudited consolidated financial statements were prepared using generally accepted accounting principles for interim financial information and the instructions to Form 10-Q and applicable rules of Regulation S-X of the SEC. Accordingly, these financial statements do not include all the footnotes required by generally accepted accounting principles for complete financial statements and should be read in conjunction with the Form 10-K. We believe all adjustments necessary for a fair presentation of these interim statements have been included and are of a normal and recurring nature. The results of operations for interim periods are not necessarily indicative of the results for the full fiscal year. Use of Estimates The preparation of financial statements in conformity with generally accepted accounting principles requires the use of estimates and assumptions by management in determining the reported amounts of assets and liabilities, revenue and expenses and disclosures regarding contingent assets and liabilities. Actual results could differ from those estimates. The most significant estimates used in our financial statements affect revenue and cost recognition for construction contracts, the allowance for doubtful accounts, self-insurance accruals, deferred tax assets, warranty accruals, fair value accounting for acquisitions and the quantification of fair value for reporting units in connection with our goodwill impairment testing. Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2014-09, “Revenue from Contracts with Customers (Topic 606).” ASU 2014-09 provides a framework that replaces the existing revenue recognition guidance. The guidance can be applied on a full retrospective or modified retrospective basis whereby the entity records a cumulative effect of initially applying this update on the adoption date. We plan to use the modified retrospective basis on the adoption date. ASU 2014-09 is effective for annual periods beginning after December 15, 2017, including interim periods within that reporting period. While we are still evaluating the potential impact of this authoritative guidance on our consolidated financial statements, we currently believe the areas that may impact us the most include accounting for variable consideration, capitalization of incremental costs of obtaining a contract and the guidance on the number of performance obligations contained in a contract. The impact on our consolidated financial statements upon adoption of ASU 2014-09 will be determined in large part by the contracts in progress on our adoption date; however, we currently do not believe the adoption will have a material impact on our consolidated financial statements. In February 2016, the FASB issued ASU No. 2016-02, “Leases (Topic 842)”. The standard requires lessees to recognize assets and liabilities for most leases. ASU 2016-02 is effective for fiscal years, and interim periods within those years, beginning after December 15, 2018. Early adoption is permitted. ASU 2016-02’s transition provisions are applied using a modified retrospective approach at the beginning of the earliest comparative period presented in the financial statements. Full retrospective application is prohibited. We are currently evaluating the potential impact of this authoritative guidance on our consolidated financial statements. In August 2016, the FASB issued ASU No. 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments”. This standard provides guidance on how certain cash receipts and cash payments are presented and classified in the statement of cash flows and is intended to reduce diversity in practice with respect to these items. The standard is applied using a retrospective transition method and is effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. Early adoption is permitted. We currently do not believe the adoption will have a material impact on our consolidated financial statements. In January 2017, the FASB issued ASU No. 2017-04, “Intangibles – Goodwill and other (Topic 350): Simplifying the Accounting for Goodwill Impairment”. This standard removes Step 2 of the goodwill impairment test, which required a hypothetical purchase price allocation. A goodwill impairment will be the amount by which a reporting unit’s carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. Additionally, entities will be required to disclose the amount of goodwill at reporting units with zero or negative carrying amounts. The standard is applied prospectively and is effective for fiscal years beginning after December 15, 2019, including annual or interim goodwill impairment tests within those fiscal years. Early adoption is permitted for interim and annual goodwill impairment tests performed on testing dates after January 1, 2017. We early adopted ASU 2017-04 in the first quarter of 2017, which did not have a material impact on our consolidated financial statements. Financial Instruments Our financial instruments consist of cash and cash equivalents, accounts receivable, other receivables, accounts payable, life insurance policies, notes to former owners, capital leases and a revolving credit facility. We believe that the carrying values of these instruments on the accompanying balance sheets approximate their fair values. Segment Disclosure Our activities are within the mechanical services industry, which is the single industry segment we serve. Each operating unit represents an operating segment and these segments have been aggregated, as the operating units meet all of the aggregation criteria.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2017
Fair Value Measurements
Fair Value Measurements	3. Fair Value Measurements We classify and disclose assets and liabilities carried at fair value in one of the following three categories: · Level 1—quoted prices in active markets for identical assets and liabilities; · Level 2—observable market based inputs or unobservable inputs that are corroborated by market data; and · Level 3—significant unobservable inputs in which little or no market data exists, therefore requiring an entity to develop its own assumptions. The following table summarizes the fair values, and levels within the fair value hierarchy in which the fair value measurements fall, for assets and liabilities measured on a recurring basis as of September 30, 2017 (in thousands): Balance Fair Value Measurements at Reporting Date September 30, 2017 Level 1 Level 2 Level 3 Cash and cash equivalents $ 29,496 $ 29,496 $ — $ — Life insurance—cash surrender value $ 3,180 $ — $ 3,180 $ — Contingent earn-out obligations $ 9,863 $ — $ — $ 9,863 Cash and cash equivalents consist primarily of highly rated money market funds at a variety of well‑known institutions with original maturities of three months or less. The original cost of these assets approximates fair value due to their short-term maturity. The carrying value of our borrowings associated with the Revolving Credit Facility approximate its fair value due to the variable rate on such debt. One of our operations has life insurance policies covering 44 employees with a combined face value of $37.3 million. The policy is invested in mutual funds and the fair value measurement of the cash surrender balance associated with these policies is determined using Level 2 inputs within the fair value hierarchy and will vary with investment performance. The cash surrender value of these policies was $3.2 million as of September 30, 2017 and $3.7 million as of December 31, 2016. These assets are included in “Other Noncurrent Assets” in our consolidated balance sheets. We value contingent earn-out obligations using a probability weighted discounted cash flow method. This fair value measurement is based on significant unobservable inputs in the market and thus represents a Level 3 measurement within the fair value hierarchy. This analysis reflects the contractual terms of the purchase agreements (e.g., minimum and maximum payments, length of earn-out periods, manner of calculating any amounts due, etc.) and utilizes assumptions with regard to future cash flows, probabilities of achieving such future cash flows and a discount rate. The contingent earn-out obligations are measured at fair value each reporting period and changes in estimates of fair value are recognized in earnings. The table below presents a reconciliation of the fair value of our contingent earn-out obligations that use significant unobservable inputs (Level 3) (in thousands). Balance at beginning of year $ 2,531 Issuances 11,755 Settlements (2,578) Adjustments to fair value (1,845) Balance at September 30, 2017 $ 9,863 We measure certain assets at fair value on a nonrecurring basis. These assets are recognized at fair value when they are deemed to be other-than-temporarily impaired. During the first quarter of 2017, we recorded a goodwill impairment charge of $1.1 million based on Level 3 measurements. See Note 5 “Goodwill” for further discussion. We did not recognize any other impairments, in the first nine months of 2017, on those assets required to be measured at fair value on a nonrecurring basis.

Acquisitions

Acquisitions	9 Months Ended
	Sep. 30, 2017
Acquisitions
Acquisitions	4. Acquisitions On April 1, 2017, we acquired all of the issued and outstanding stock of BCH Holdings, Inc. and each of its wholly-owned subsidiaries (collectively “BCH”) for $100 million, comprised of $85.7 million in cash at closing and $14.3 million in a note payable to the former owners, plus an earn‑out that we will pay if certain financial targets are met after the acquisition date and a working capital adjustment. The preliminary acquisition date fair value of consideration transferred for this acquisition was $122.6 million, of which $97.9 million was allocated to goodwill and identifiable intangible assets. Our consolidated operating results included revenue of $73.2 million for the six months from the acquisition date. BCH is an integrated, single-source provider of mechanical service, maintenance and construction with headquarters in Tampa, Florida and operations throughout the southeastern region of the United States, which reports as a separate operating location. We completed two acquisitions in the first quarter of 2016. We acquired the remaining 40% noncontrolling interest in Environmental Air Systems, LLC (“EAS”) on January 1, 2016 for $46.6 million, including $42.0 million funded on the closing date plus a holdback, an earn-out that will be earned if certain financial targets are met after the acquisition date and a working capital adjustment. Due to our majority ownership and control over EAS on the acquisition date, the difference between the purchase price and the noncontrolling interest liability was recorded in Additional Paid-In Capital in our Balance Sheet. Additionally in the first quarter of 2016, we acquired 100% of the ShoffnerKalthoff family of companies (collectively, “Shoffner”), which reports as a separate operating location in the Knoxville, Tennessee area. The acquisition date fair value of consideration transferred for this acquisition was $19.8 million, of which $14.8 million was allocated to goodwill and identifiable intangible assets. The purchase price included $15.5 million funded on the closing date plus a note payable to the former owners, an earn-out that we will pay if certain financial targets are met after the acquisition date and a working capital adjustment. In addition to the BCH acquisition, we completed three additional acquisitions in the second quarter of 2017. We completed one acquisition in the third quarter of 2017. The total purchase price for these acquisitions, including earn-outs, was $9.6 million for the nine months ended September 30, 2017. These acquisitions were not material and were “tucked-in” with existing operations. The results of operations of acquisitions are included in our consolidated financial statements from their respective acquisition dates. Our consolidated balance sheet includes preliminary allocations of the purchase price to the assets acquired and liabilities assumed for the applicable acquisition pending the completion of the final valuation of intangible assets and accrued liabilities. The acquisitions completed in the current and prior year were not material, individually or in the aggregate. Additional contingent purchase price (“earn-out”) has been or will be paid if certain acquisitions achieve predetermined profitability targets. Such earn-outs are not subject to the continued employment of the sellers .

Goodwill

Goodwill	9 Months Ended
	Sep. 30, 2017
Goodwill
Goodwill	5. Goodwill The changes in the carrying amount of goodwill are as follows (in thousands): September 30, December 31, 2017 2016 Balance at beginning of year $ 149,208 $ 143,874 Additions (See Note 4) 55,668 5,334 Impairment adjustment (1,105) — Balance at end of period $ 203,771 $ 149,208 We recorded a goodwill impairment charge of $1.1 million during the first quarter of 2017. Based on changes to our market strategy that occurred in March 2017 related to our reporting unit based in California, we reevaluated our projected future earnings for this operating location. When the carrying value of a given reporting unit exceeds its fair value, a goodwill impairment loss is recorded for this difference, not to exceed the carrying amount of goodwill. Based upon our projected future earnings for this location, we could no longer support the related goodwill balance and therefore the goodwill associated with this location was fully impaired. The fair value was estimated using a discounted cash flow model.

Debt Obligations

Debt Obligations	9 Months Ended
	Sep. 30, 2017
Debt Obligations
Debt Obligations	6. Debt Obligations Debt obligations consist of the following (in thousands): September 30, December 31, 2017 2016 Revolving credit facility $ 66,000 $ — Notes to former owners 15,330 2,250 Other debt 239 305 Capital lease obligations 123 256 Total debt 81,692 2,811 Less—current portion (708) (763) Total long-term portion of debt $ 80,984 $ Revolving Credit Facility We have a $325.0 million senior credit facility (the “Facility”) provided by a syndicate of banks, with a $100 million accordion option. The Facility, which is available for borrowings and letters of credit, expires in February 2021 and is secured by a first lien on substantially all of our personal property except for assets related to projects subject to surety bonds and assets held by certain unrestricted subsidiaries and a second lien on our assets related to projects subject to surety bonds. As of September 30, 2017, we had $66.0 million of outstanding borrowings, $39.6 million in letters of credit outstanding and $219.4 million of credit available. There are two interest rate options for borrowings under the Facility, the Base Rate Loan Option and the Eurodollar Rate Loan Option. These rates are floating rates determined by the broad financial markets, meaning they can and do move up and down from time to time. Additional margins are then added to these two rates. The following is a summary of the additional margins: Consolidated Total Indebtedness to Credit Facility Adjusted EBITDA Less than 0.75 0.75 to 1.50 1.50 to 2.25 2.25 or greater Additional Per Annum Interest Margin Added Under: Base Rate Loan Option 0.25 % 0.50 % 0.75 % 1.00 % Eurodollar Rate Loan Option 1.25 % 1.50 % 1.75 % 2.00 % The weighted average interest rate applicable to the borrowings under the Facility was approximately 2.6% as of September 30, 2017. Certain of our vendors require letters of credit to ensure reimbursement for amounts they are disbursing on our behalf, such as to beneficiaries under our self-funded insurance programs. We have also occasionally used letters of credit to guarantee performance under our contracts and to ensure payment to our subcontractors and vendors under those contracts. Our lenders issue such letters of credit through the Facility for a fee. We have never had a claim made against a letter of credit that resulted in payments by a lender or by us and believe such a claim is unlikely in the foreseeable future. The letter of credit fees range from 1.25% to 2.00% per annum, based on the ratio of Consolidated Total Indebtedness to Credit Facility Adjusted EBITDA, as defined in the credit agreement. Commitment fees are payable on the portion of the revolving loan capacity not in use for borrowings or letters of credit at any given time. These fees range from 0.20% to 0.35% per annum, based on the ratio of Consolidated Total Indebtedness to Credit Facility Adjusted EBITDA, as defined in the credit agreement. The Facility contains financial covenants defining various financial measures and the levels of these measures with which we must comply. Covenant compliance is assessed as of each quarter end. The Facility’s principal financial covenants include: Leverage Ratio —The Facility requires that the ratio of our Consolidated Total Indebtedness to our Credit Facility Adjusted EBITDA not exceed (i) 3.00 to 1.00 as of the end of each fiscal quarter through September 30, 2017, and (ii) 2.75 to 1.00 as of the end of each fiscal quarter thereafter through maturity. The leverage ratio as of September 30, 2017 was 0.5. Fixed Charge Coverage Ratio —The Facility requires that the ratio of (a) Credit Facility Adjusted EBITDA, less non-financed capital expenditures, tax provision, dividends and amounts used to repurchase stock to (b) the sum of interest expense and scheduled principal payments of indebtedness be at least 2.00 to 1.00; provided that the calculation of the fixed charge coverage ratio excludes stock repurchases and the payment of dividends at any time that the Company’s Net Leverage Ratio does not exceed 1.50 to 1.00. The Facility also allows the fixed charge coverage ratio not to be reduced for stock repurchases through September 30, 2015 in an aggregate amount not to exceed $25 million and for stock repurchases made after February 22, 2016 but on or prior to December 31, 2017 in an aggregate amount not to exceed $25 million, if at the time of and after giving effect to such repurchase the Company’s Net Leverage Ratio was less than or equal to 1.50 to 1.00. Capital expenditures, tax provision, dividends and stock repurchase payments are defined under the Facility for purposes of this covenant to be amounts for the four quarters ending as of any given quarterly covenant compliance measurement date. The fixed charge coverage ratio as of September 30, 2017 was 29.5. Other Restrictions —The Facility permits acquisitions of up to $30.0 million per transaction, provided that the aggregate purchase price of all such acquisitions in the same fiscal year does not exceed $65.0 million. However, these limitations only apply when the Company’s Total Leverage Ratio is greater than 2.00 to 1.00. While the Facility’s financial covenants do not specifically govern capacity under the Facility, if our debt level under the Facility at a quarter-end covenant compliance measurement date were to cause us to violate the Facility’s leverage ratio covenant, our borrowing capacity under the Facility and the favorable terms that we currently have could be negatively impacted by the lenders. We were in compliance with all of our financial covenants as of September 30, 2017. Notes to Former Owners As part of the consideration used to acquire two companies, we have outstanding notes to the former owners. These notes had an outstanding balance of $15.3 million as of September 30, 2017. In conjunction with the BCH acquisition in the second quarter of 2017, we issued a promissory note to former owners with an outstanding balance of $14.3 million as of September 30, 2017 that bears interest, payable quarterly, at a weighted average interest rate of 3.0%. The principal is due in equal installments in April 2020 and 2021. In conjunction with the Shoffner acquisition in the first quarter of 2016, we issued a subordinated note to former owners with an outstanding balance of $1.0 million as of September 30, 2017 that bears interest, payable quarterly, at a weighted average interest rate of 3.0%. The principal is due in equal installments in February 2018 and 2019. Other Debt As part of the Shoffner acquisition, we acquired debt with an outstanding balance at the acquisition date of $0.4 million with principal and interest due the last day of every month; ending on the December 30, 2019 maturity date. The interest rate is the one month LIBOR rate plus 2.25%. As of September 30, 2017, $0.2 million of the note was outstanding, of which $0.1 million was considered current. In addition, with one of our acquisitions we acquired capital lease obligations. As of September 30, 2017, $0.1 million of capital lease obligations were outstanding, of which $0.1 million was considered current.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2017
Commitments and Contingencies
Commitments and Contingencies	7. Commitments and Contingencies Claims and Lawsuits We are subject to certain legal and regulatory claims, including lawsuits arising in the normal course of business. We maintain various insurance coverages to minimize financial risk associated with these claims. We have estimated and provided accruals for probable losses and related legal fees associated with certain litigation in the accompanying consolidated financial statements. While we cannot predict the outcome of these proceedings, in management’s opinion and based on reports of counsel, any liability arising from these matters individually and in the aggregate will not have a material effect on our operating results, cash flows or financial condition, after giving effect to provisions already recorded. Surety Many customers, particularly in connection with new construction, require us to post performance and payment bonds issued by a financial institution known as a surety. If we fail to perform under the terms of a contract or to pay subcontractors and vendors who provided goods or services under a contract, the customer may demand that the surety make payments or provide services under the bond. We must reimburse the surety for any expenses or outlays it incurs. To date, we are not aware of any losses to our sureties in connection with bonds the sureties have posted on our behalf, and do not expect such losses to be incurred in the foreseeable future. Surety market conditions have seen some strengthening as the commercial construction markets have started to rebound. Bonding capacity remains adequate in the current market conditions along with acceptable terms and conditions. Historically, approximately 20% to 30% of our business has required bonds. While we currently have strong surety relationships to support our bonding needs, future market conditions or changes in the sureties’ assessment of our operating and financial risk could cause the sureties to decline to issue bonds for our work. If that were to occur, the alternatives include doing more business that does not require bonds, posting other forms of collateral for project performance such as letters of credit or cash, and seeking bonding capacity from other sureties. We would likely also encounter concerns from customers, suppliers and other market participants as to our creditworthiness. While we believe our general operating and financial characteristics would enable us to ultimately respond effectively to an interruption in the availability of bonding capacity, such an interruption would likely cause our revenue and profits to decline in the near term. Self-Insurance We are substantially self‑insured for workers’ compensation, employer’s liability, auto liability, general liability and employee group health claims, in view of the relatively high per‑incident deductibles we absorb under our insurance arrangements for these risks. Losses are estimated and accrued based upon known facts, historical trends and industry averages. Estimated losses in excess of our deductible, which have not already been paid, are included in our accrual with a corresponding receivable from our insurance carrier. Loss estimates associated with the larger and longer‑developing risks, such as workers’ compensation, auto liability and general liability, are reviewed by a third‑party actuary quarterly.

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2017
Stockholders' Equity
Stockholders' Equity	8. Stockholders’ Equity Earnings Per Share Basic earnings per share (“EPS”) is computed by dividing net income by the weighted average number of shares of common stock outstanding during the year. Diluted EPS is computed considering the dilutive effect of stock options, restricted stock, restricted stock units and performance stock units. The vesting of unvested contingently issuable performance stock units is based on the achievement of certain earnings per share targets and total shareholder return. These shares are considered contingently issuable shares for purposes of calculating diluted earnings per share. These shares are not included in the diluted earnings per share denominator until the performance criteria are met, if it is assumed that the end of the reporting period was the end of the contingency period. Unvested restricted stock, restricted stock units and performance stock units are included in diluted earnings per share, weighted outstanding until the shares and units vest. Upon vesting, the vested restricted stock, restricted stock units and performance stock units are included in basic earnings per share weighted outstanding from the vesting date. There were less than 0.1 million anti-dilutive stock options for the three and nine months ended September 30, 2017. There were approximately 0.1 million anti-dilutive stock options excluded from the calculation of diluted EPS for the three and nine months ended September 30, 2016. The following table reconciles the number of shares outstanding with the number of shares used in computing basic and diluted earnings per share for each of the periods presented (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2017 2016 2017 2016 Common shares outstanding, end of period 37,134 37,230 37,134 37,230 Effect of using weighted average common shares outstanding 98 130 125 150 Shares used in computing earnings per share—basic 37,232 37,360 37,259 37,380 Effect of shares issuable under stock option plans based on the treasury stock method 293 319 312 331 Effect of restricted and contingently issuable shares 101 142 113 143 Shares used in computing earnings per share—diluted 37,626 37,821 37,684 37,854 Share Repurchase Program On March 29, 2007, our Board of Directors (the “Board”) approved a stock repurchase program to acquire up to 1.0 million shares of our outstanding common stock. Subsequently, the Board has from time to time approved extensions of the program to acquire additional shares. Since the inception of the repurchase program, the Board has approved 8.1 million shares to be repurchased. As of September 30, 2017, we have repurchased a cumulative total of 7.6 million shares at an average price of $13.75 per share under the repurchase program. The share repurchases will be made from time to time at our discretion in the open market or privately negotiated transactions as permitted by securities laws and other legal requirements, and subject to market conditions and other factors. The Board may modify, suspend, extend or terminate the program at any time. During the nine months ended September 30, 2017, we repurchased 0.3 million shares for approximately $8.9 million at an average price of $34.18 per share.

Summary of Significant Accoun15

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2017
Summary of Significant Accounting Policies
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with generally accepted accounting principles requires the use of estimates and assumptions by management in determining the reported amounts of assets and liabilities, revenue and expenses and disclosures regarding contingent assets and liabilities. Actual results could differ from those estimates. The most significant estimates used in our financial statements affect revenue and cost recognition for construction contracts, the allowance for doubtful accounts, self-insurance accruals, deferred tax assets, warranty accruals, fair value accounting for acquisitions and the quantification of fair value for reporting units in connection with our goodwill impairment testing.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2014-09, “Revenue from Contracts with Customers (Topic 606).” ASU 2014-09 provides a framework that replaces the existing revenue recognition guidance. The guidance can be applied on a full retrospective or modified retrospective basis whereby the entity records a cumulative effect of initially applying this update on the adoption date. We plan to use the modified retrospective basis on the adoption date. ASU 2014-09 is effective for annual periods beginning after December 15, 2017, including interim periods within that reporting period. While we are still evaluating the potential impact of this authoritative guidance on our consolidated financial statements, we currently believe the areas that may impact us the most include accounting for variable consideration, capitalization of incremental costs of obtaining a contract and the guidance on the number of performance obligations contained in a contract. The impact on our consolidated financial statements upon adoption of ASU 2014-09 will be determined in large part by the contracts in progress on our adoption date; however, we currently do not believe the adoption will have a material impact on our consolidated financial statements. In February 2016, the FASB issued ASU No. 2016-02, “Leases (Topic 842)”. The standard requires lessees to recognize assets and liabilities for most leases. ASU 2016-02 is effective for fiscal years, and interim periods within those years, beginning after December 15, 2018. Early adoption is permitted. ASU 2016-02’s transition provisions are applied using a modified retrospective approach at the beginning of the earliest comparative period presented in the financial statements. Full retrospective application is prohibited. We are currently evaluating the potential impact of this authoritative guidance on our consolidated financial statements. In August 2016, the FASB issued ASU No. 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments”. This standard provides guidance on how certain cash receipts and cash payments are presented and classified in the statement of cash flows and is intended to reduce diversity in practice with respect to these items. The standard is applied using a retrospective transition method and is effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. Early adoption is permitted. We currently do not believe the adoption will have a material impact on our consolidated financial statements. In January 2017, the FASB issued ASU No. 2017-04, “Intangibles – Goodwill and other (Topic 350): Simplifying the Accounting for Goodwill Impairment”. This standard removes Step 2 of the goodwill impairment test, which required a hypothetical purchase price allocation. A goodwill impairment will be the amount by which a reporting unit’s carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. Additionally, entities will be required to disclose the amount of goodwill at reporting units with zero or negative carrying amounts. The standard is applied prospectively and is effective for fiscal years beginning after December 15, 2019, including annual or interim goodwill impairment tests within those fiscal years. Early adoption is permitted for interim and annual goodwill impairment tests performed on testing dates after January 1, 2017. We early adopted ASU 2017-04 in the first quarter of 2017, which did not have a material impact on our consolidated financial statements.
Financial Instruments	Financial Instruments Our financial instruments consist of cash and cash equivalents, accounts receivable, other receivables, accounts payable, life insurance policies, notes to former owners, capital leases and a revolving credit facility. We believe that the carrying values of these instruments on the accompanying balance sheets approximate their fair values.
Segment Disclosure	Segment Disclosure Our activities are within the mechanical services industry, which is the single industry segment we serve. Each operating unit represents an operating segment and these segments have been aggregated, as the operating units meet all of the aggregation criteria.

Business and Organization (Tabl

Business and Organization (Tables)	9 Months Ended
	Sep. 30, 2017
Business and Organization
Schedule of service activities	Revenue Service Activity $ in thousands % HVAC and Plumbing $ 1,207,434 91 % Building Automation Control Systems 66,343 5 % Other 53,073 4 % Total $ 1,326,850 100 %

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2017
Fair Value Measurements
Summary of fair values and levels within the fair value hierarchy in which the fair value measurements fall for assets and liabilities measured on a recurring basis	The following table summarizes the fair values, and levels within the fair value hierarchy in which the fair value measurements fall, for assets and liabilities measured on a recurring basis as of September 30, 2017 (in thousands): Balance Fair Value Measurements at Reporting Date September 30, 2017 Level 1 Level 2 Level 3 Cash and cash equivalents $ 29,496 $ 29,496 $ — $ — Life insurance—cash surrender value $ 3,180 $ — $ 3,180 $ — Contingent earn-out obligations $ 9,863 $ — $ — $ 9,863
Schedule of reconciliation of the fair value of contingent earn-out obligations that use significant unobservable inputs (Level 3)	The table below presents a reconciliation of the fair value of our contingent earn-out obligations that use significant unobservable inputs (Level 3) (in thousands). Balance at beginning of year $ 2,531 Issuances 11,755 Settlements (2,578) Adjustments to fair value (1,845) Balance at September 30, 2017 $ 9,863

Goodwill (Tables)

Goodwill (Tables)	9 Months Ended
	Sep. 30, 2017
Goodwill
Schedule of changes in the carrying amount of goodwill	The changes in the carrying amount of goodwill are as follows (in thousands): September 30, December 31, 2017 2016 Balance at beginning of year $ 149,208 $ 143,874 Additions (See Note 4) 55,668 5,334 Impairment adjustment (1,105) — Balance at end of period $ 203,771 $ 149,208

Debt Obligations (Tables)

Debt Obligations (Tables)	9 Months Ended
	Sep. 30, 2017
Debt Obligations
Schedule of components of debt obligations	Debt obligations consist of the following (in thousands): September 30, December 31, 2017 2016 Revolving credit facility $ 66,000 $ — Notes to former owners 15,330 2,250 Other debt 239 305 Capital lease obligations 123 256 Total debt 81,692 2,811 Less—current portion (708) (763) Total long-term portion of debt $ 80,984 $
Summary of additional margins	Consolidated Total Indebtedness to Credit Facility Adjusted EBITDA Less than 0.75 0.75 to 1.50 1.50 to 2.25 2.25 or greater Additional Per Annum Interest Margin Added Under: Base Rate Loan Option 0.25 % 0.50 % 0.75 % 1.00 % Eurodollar Rate Loan Option 1.25 % 1.50 % 1.75 % 2.00 %

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2017
Stockholders' Equity
Reconciliation of number of shares outstanding with the number of shares used in computing basic and diluted earnings per share	The following table reconciles the number of shares outstanding with the number of shares used in computing basic and diluted earnings per share for each of the periods presented (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2017 2016 2017 2016 Common shares outstanding, end of period 37,134 37,230 37,134 37,230 Effect of using weighted average common shares outstanding 98 130 125 150 Shares used in computing earnings per share—basic 37,232 37,360 37,259 37,380 Effect of shares issuable under stock option plans based on the treasury stock method 293 319 312 331 Effect of restricted and contingently issuable shares 101 142 113 143 Shares used in computing earnings per share—diluted 37,626 37,821 37,684 37,854

Business and Organization (Deta

Business and Organization (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Business and Organization
Revenue	$ 480,851	$ 428,760	$ 1,326,850	$ 1,242,240
Percentage of revenue attributable to services			100.00%
Installation of systems in newly constructed facilities
Business and Organization
Percentage of revenue attributable to services			37.00%
Maintenance, repair and replacement services
Business and Organization
Percentage of revenue attributable to services			63.00%
Heating Ventilation Air Conditioning And Plumbing [Member]
Business and Organization
Revenue			$ 1,207,434
Percentage of revenue attributable to services			91.00%
Building Automation Control Systems
Business and Organization
Revenue			$ 66,343
Percentage of revenue attributable to services			5.00%
Other
Business and Organization
Revenue			$ 53,073
Percentage of revenue attributable to services			4.00%

Fair Value Measurements (Detail

Fair Value Measurements (Details) $ in Thousands	3 Months Ended	9 Months Ended
	Mar. 31, 2017USD ($)	Sep. 30, 2017USD ($)item	Dec. 31, 2016USD ($)
Fair Value Measurements
Number of employees covered under life insurance policies | item		44
Combined face value of life insurance policies		$ 37,300
Cash surrender value		3,200	$ 3,700
Reconciliation of the fair value of contingent earn-out obligations that use significant unobservable inputs (Level 3)
Goodwill, Impairment Loss	$ 1,100	1,105
Contingent earn-out obligations
Reconciliation of the fair value of contingent earn-out obligations that use significant unobservable inputs (Level 3)
Balance at beginning of year	2,531	2,531
Issuances		11,755
Settlements		(2,578)
Adjustments to fair value		(1,845)
Balance at end of period		9,863
Recurring basis | Total
Fair Value Measurements
Cash and cash equivalents		29,496
Life insurance - cash surrender value		3,180
Contingent earn-out obligations		9,863
Recurring basis | Quoted Market Prices In Active Markets for Identical Assets (Level 1)
Fair Value Measurements
Cash and cash equivalents		29,496
Recurring basis | Fair Value Measurements at Reporting Date Using Significant Other Observable Inputs (Level 2)
Fair Value Measurements
Life insurance - cash surrender value		3,180
Recurring basis | Significant Unobservable Inputs (Level 3)
Fair Value Measurements
Contingent earn-out obligations		$ 9,863
Non recurring basis | Significant Unobservable Inputs (Level 3)
Reconciliation of the fair value of contingent earn-out obligations that use significant unobservable inputs (Level 3)
Goodwill, Impairment Loss	$ 1,100

Acquisitions (Details)

Acquisitions (Details) $ in Millions	Jun. 30, 2017item	Apr. 01, 2017USD ($)	Jan. 01, 2016USD ($)	Sep. 30, 2017USD ($)item	Jun. 30, 2017item	Mar. 31, 2016item	Sep. 30, 2017USD ($)
Acquisitions
Number of acquisitions | item				1	3	2
Total purchase price							$ 9.6
Notes to former owners
Acquisitions
Number of acquisitions | item	2
Environmental Air Systems
Acquisitions
Interest acquired (as a percent)			40.00%
Total purchase price			$ 46.6
Purchase price paid in cash			$ 42
Shoffner
Acquisitions
Interest acquired (as a percent)						100.00%
Total purchase price							19.8
Amount allocated to goodwill and identifiable intangible assets for acquisitions				$ 14.8			14.8
Purchase price paid in cash							15.5
BCH
Acquisitions
Total purchase price		$ 100					122.6
Amount allocated to goodwill and identifiable intangible assets for acquisitions				$ 97.9			97.9
Revenue in consolidated results							$ 73.2
Purchase price paid in cash		85.7
Promissory note payable		$ 14.3

Goodwill (Details)

Goodwill (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
	Mar. 31, 2017	Sep. 30, 2017	Dec. 31, 2016
Changes in the carrying amount of goodwill
Balance at the beginning of year	$ 149,208	$ 149,208	$ 143,874
Additions (See Note 4)		55,668	5,334
Impairment adjustment	$ (1,100)	(1,105)
Balance at end of period		$ 203,771	$ 149,208

Debt Obligations (Details)

Debt Obligations (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Long-Term Debt Obligations
Total debt	$ 81,692	$ 2,811
Less - current portion	(708)	(763)
Total long-term portion of debt	80,984	2,048
Revolving credit facility
Long-Term Debt Obligations
Total debt	66,000
Notes to former owners
Long-Term Debt Obligations
Total debt	15,330	2,250
Other debt
Long-Term Debt Obligations
Total debt	239	305
Capital lease obligation	100
Capital lease obligations
Long-Term Debt Obligations
Capital lease obligation	$ 123	$ 256

Debt Obligations-Other (Details

Debt Obligations-Other (Details) $ in Thousands	Jun. 30, 2017item	Apr. 01, 2017USD ($)	Sep. 30, 2017USD ($)item	Jun. 30, 2017item	Mar. 31, 2016item	Sep. 30, 2017USD ($)item	Dec. 31, 2016USD ($)
Long-Term Debt Obligations
Line of credit borrowing capacity accordion option			$ 100,000			$ 100,000
Other disclosures
Current portion of capital lease obligations			$ 90			90	$ 163
Number of acquisitions | item			1	3	2
Shoffner
Other disclosures
Outstanding balance			$ 200			200
Debt acquired related to coil line duct processing system			400			400
Current debt			100			$ 100
BCH
Other disclosures
Promissory note payable		$ 14,300
London Interbank Offered Rate (LIBOR) | Shoffner
Market rates relating to interest options
Interest rate margin (as a percent)						2.25%
Additional per annum interest margin added under:
Additional per annum interest margin (as a percent)						2.25%
Revolving credit facility
Long-Term Debt Obligations
Borrowing capacity			325,000			$ 325,000
Letters of credit amount outstanding			39,600			39,600
Credit available			$ 219,400			$ 219,400
Principal financial covenants
Leverage ratio			0.50			0.50
Fixed charge coverage ratio			29.5			29.5
Number of quarters of capital expenditures, tax provision, dividends and stock repurchase payments used for calculation of fixed charge coverage ratio | item						4
Number of interest rate options | item						2
Other disclosures
Outstanding balance			$ 66,000			$ 66,000
Weighted average interest rate (as a percent)			2.60%			2.60%
Revolving credit facility | Through September 30, 2017
Principal financial covenants
Leverage ratio			3			3
Revolving credit facility | Through maturity
Principal financial covenants
Leverage ratio			2.75			2.75
Revolving credit facility | Minimum
Principal financial covenants
Fixed charge coverage ratio			2			2
Additional per annum interest margin added under:
Letter of credit fees (as a percent)						1.25%
Commitment fees payable on unused portion of the facility (as a percent)						0.20%
Revolving credit facility | Minimum | Covenant Requirement
Principal financial covenants
Net leverage ratio used as basis for other restrictions			2			2
Revolving credit facility | Maximum
Principal financial covenants
Net leverage ratio after giving effect to stock repurchases for calculation of the fixed charge coverage ratio			1.50			1.50
Permitted amount of acquisitions per transaction			$ 30,000			$ 30,000
Aggregate purchase price of current acquisition and acquisitions in the preceding 12 month period for determining permitted amount of acquisition per transaction			$ 65,000			$ 65,000
Additional per annum interest margin added under:
Letter of credit fees (as a percent)						2.00%
Commitment fees payable on unused portion of the facility (as a percent)						0.35%
Revolving credit facility | Maximum | Covenant Requirement
Principal financial covenants
Net leverage ratio used to determine exclusion of stock repurchases and the payment of dividends for calculation of the fixed charge coverage ratio			1.50			1.50
Revolving credit facility | Maximum | Stock Repurchases Through September 30, 2015
Principal financial covenants
Amount of stock repurchases to maintain maximum net leverage ratio						$ 25,000
Revolving credit facility | Maximum | Stock Repurchases After February 22, 2016 And On Or Before December 31, 2017
Principal financial covenants
Amount of stock repurchases to maintain maximum net leverage ratio						$ 25,000
Revolving credit facility | Base rate | Consolidated Total Indebtedness to Credit Facility Adjusted EBITDA: Less than 0.75
Market rates relating to interest options
Interest rate margin (as a percent)						0.25%
Additional per annum interest margin added under:
Additional per annum interest margin (as a percent)						0.25%
Revolving credit facility | Base rate | Consolidated Total Indebtedness to Credit Facility Adjusted EBITDA: 0.75 to 1.50
Market rates relating to interest options
Interest rate margin (as a percent)						0.50%
Additional per annum interest margin added under:
Additional per annum interest margin (as a percent)						0.50%
Revolving credit facility | Base rate | Consolidated Total Indebtedness to Credit Facility Adjusted EBITDA: 1.50 to 2.25
Market rates relating to interest options
Interest rate margin (as a percent)						0.75%
Additional per annum interest margin added under:
Additional per annum interest margin (as a percent)						0.75%
Revolving credit facility | Base rate | Consolidated Total Indebtedness to Credit Facility Adjusted EBITDA: 2.25 or greater
Market rates relating to interest options
Interest rate margin (as a percent)						1.00%
Additional per annum interest margin added under:
Additional per annum interest margin (as a percent)						1.00%
Revolving credit facility | Eurodollar rate | Consolidated Total Indebtedness to Credit Facility Adjusted EBITDA: Less than 0.75
Market rates relating to interest options
Interest rate margin (as a percent)						1.25%
Additional per annum interest margin added under:
Additional per annum interest margin (as a percent)						1.25%
Revolving credit facility | Eurodollar rate | Consolidated Total Indebtedness to Credit Facility Adjusted EBITDA: 0.75 to 1.50
Market rates relating to interest options
Interest rate margin (as a percent)						1.50%
Additional per annum interest margin added under:
Additional per annum interest margin (as a percent)						1.50%
Revolving credit facility | Eurodollar rate | Consolidated Total Indebtedness to Credit Facility Adjusted EBITDA: 1.50 to 2.25
Market rates relating to interest options
Interest rate margin (as a percent)						1.75%
Additional per annum interest margin added under:
Additional per annum interest margin (as a percent)						1.75%
Revolving credit facility | Eurodollar rate | Consolidated Total Indebtedness to Credit Facility Adjusted EBITDA: 2.25 or greater
Market rates relating to interest options
Interest rate margin (as a percent)						2.00%
Additional per annum interest margin added under:
Additional per annum interest margin (as a percent)						2.00%
Notes to former owners
Other disclosures
Outstanding balance			$ 15,330			$ 15,330	2,250
Number of acquisitions | item	2
Subordinate note | Shoffner
Other disclosures
Outstanding balance			$ 1,000			$ 1,000
Weighted average interest rate (as a percent)			3.00%			3.00%
Promissory note | BCH
Other disclosures
Outstanding balance			$ 14,300			$ 14,300
Weighted average interest rate (as a percent)			3.00%			3.00%
Other debt
Other disclosures
Outstanding balance			$ 239			$ 239	$ 305
Capital lease obligation pertaining to acquisition			100			100
Current portion of capital lease obligations			$ 100			$ 100

Commitments and Contingencies -

Commitments and Contingencies - Bonds (Details) - Surety	9 Months Ended
	Sep. 30, 2017
Minimum
Surety
Percentage of business which has required bonds	20.00%
Maximum
Surety
Percentage of business which has required bonds	30.00%

Stockholders' Equity- Anti-dilu

Stockholders' Equity- Anti-dilutive stock options (Details) - Stock Options - shares shares in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Earnings Per Share
Anti-dilutive securities excluded from computation of earnings per share amount (in shares)		0.1		0.1
Maximum
Earnings Per Share
Anti-dilutive securities excluded from computation of earnings per share amount (in shares)	0.1		0.1

Stockholders' Equity-Number of

Stockholders' Equity-Number of Shares (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Reconciliation of the number of shares outstanding with the number of shares used in computing basic and diluted earnings per share
Common shares outstanding, end of period	37,134	37,230	37,134	37,230
Effect of using weighted average common shares outstanding	98	130	125	150
Shares used in computing earnings per share - basic	37,232	37,360	37,259	37,380
Effect of shares issuable under stock option plans based on the treasury stock method	293	319	312	331
Effect of restricted and contingently issuable shares	101	142	113	143
Shares used in computing earnings per share - diluted	37,626	37,821	37,684	37,854

Stockholders' Equity- Incentive

Stockholders' Equity- Incentive and Other (Details) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions	9 Months Ended		126 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Mar. 29, 2007
Share Repurchase Program
Payments for Repurchase of Common Stock	$ 8,909	$ 10,977
Stock Repurchase Program 2007 [Member]
Share Repurchase Program
Number of shares of outstanding common stock authorized to be acquired under a stock repurchase program	8.1		8.1	1
Share repurchase (in shares)			7.6
Average price (in dollars per share)	$ 34.18		$ 13.75
Payments for Repurchase of Common Stock	$ 8,900
Stock Repurchase Program 2007 [Member] | Maximum
Share Repurchase Program
Share repurchase (in shares)	0.3