Mantech International (MANT) 10-Q 1 Nov 19 2019 Q3 Quarterly report Financial data

Cover Page Cover Page

Cover Page Cover Page - shares	9 Months Ended
	Sep. 30, 2019	Oct. 30, 2019
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2019
Document Transition Report	false
Entity File Number	000-49604
Entity Registrant Name	ManTech International Corp
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	22-1852179
Entity Address, Address Line One	2251 Corporate Park Drive
Entity Address, City or Town	Herndon
Entity Address, State or Province	VA
Entity Address, Postal Zip Code	20171
City Area Code	703
Local Phone Number	218-6000
Title of 12(b) Security	Class A Common Stock
Trading Symbol	MANT
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Small Reporting Company	false
Emerging Growth Company	false
Entity Shell Company	false
Amendment Flag	false
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Entity Central Index Key	0000892537
Current Fiscal Year End Date	--12-31
Class A common stock
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		26,913,779
Class B common stock
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		13,188,045

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($)	Sep. 30, 2019	Dec. 31, 2018
ASSETS
Cash and cash equivalents	$ 33,313,000	$ 5,294,000
Receivables—net	367,042,000	405,378,000
Prepaid expenses	26,069,000	23,398,000
Other current assets	7,152,000	5,915,000
Total Current Assets	433,576,000	439,985,000
Goodwill	1,191,213,000	1,085,806,000
Other intangible assets—net	203,247,000	171,962,000
Operating lease right of use assets	116,236,000	0
Property and equipment—net	72,993,000	51,427,000
Employee supplemental savings plan assets	34,897,000	30,501,000
Investments	11,550,000	11,830,000
Other assets	14,127,000	12,360,000
TOTAL ASSETS	2,077,839,000	1,803,871,000
LIABILITIES
Accounts payable and accrued expenses	161,404,000	126,066,000
Accrued salaries and related expenses	104,309,000	89,058,000
Contract liabilities	43,891,000	28,209,000
Operating lease liabilities—current	28,170,000	0
Total Current Liabilities	337,774,000	243,333,000
Long term debt	25,000,000	7,500,000
Deferred income taxes	126,048,000	108,956,000
Operating lease liabilities—long term	98,979,000	0
Accrued retirement	33,654,000	30,999,000
Other long-term liabilities	1,428,000	11,889,000
TOTAL LIABILITIES	622,883,000	402,677,000
COMMITMENTS AND CONTINGENCIES
STOCKHOLDERS' EQUITY
Additional paid-in capital	519,835,000	506,970,000
Treasury stock	(9,158,000)	(9,158,000)
Retained earnings	943,969,000	903,084,000
Accumulated other comprehensive loss	(93,000)	(102,000)
TOTAL STOCKHOLDERS’ EQUITY	1,454,956,000	1,401,194,000
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	2,077,839,000	1,803,871,000
Class A common stock
STOCKHOLDERS' EQUITY
Common stock	271,000	268,000
TOTAL STOCKHOLDERS’ EQUITY	271,000	268,000
Class B common stock
STOCKHOLDERS' EQUITY
Common stock	132,000	132,000
TOTAL STOCKHOLDERS’ EQUITY	$ 132,000	$ 132,000

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets Parentheticals - $ / shares	Sep. 30, 2019	Dec. 31, 2018
Treasury stock, Shares	244,113	244,113
Class A common stock
Common stock, Par value per share	$ 0.01	$ 0.01
Common stock, Shares authorized	150,000,000	150,000,000
Common stock, Shares issued	27,149,693	26,817,513
Common stock, Shares outstanding	26,905,580	26,573,400
Class B common stock
Common stock, Par value per share	$ 0.01	$ 0.01
Common stock, Shares authorized	50,000,000	50,000,000
Common stock, Shares issued	13,188,045	13,188,045
Common stock, Shares outstanding	13,188,045	13,188,045

Condensed Consolidated Statemen

Condensed Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
REVENUE	$ 579,179	$ 497,205	$ 1,618,146	$ 1,461,485
Cost of services	487,914	425,560	1,378,263	1,250,505
General and administrative expenses	52,863	42,246	139,652	126,831
OPERATING INCOME	38,402	29,399	100,231	84,149
Interest expense	(659)	(616)	(2,088)	(2,007)
Interest income	90	43	401	85
Other income (expense), net	(39)	1	(50)	63
INCOME FROM OPERATIONS BEFORE INCOME TAXES AND EQUITY METHOD INVESTMENTS	37,794	28,827	98,494	82,290
Provision for income taxes	(9,873)	(6,912)	(25,229)	(20,412)
Equity in earnings of unconsolidated subsidiaries	16	8	4	27
NET INCOME	$ 27,937	$ 21,923	$ 73,269	$ 61,905
Class A common stock
BASIC EARNINGS PER SHARE:
Basic earnings per share	$ 0.70	$ 0.55	$ 1.84	$ 1.57
DILUTED EARNINGS PER SHARE:
Diluted earnings per share	0.69	0.55	1.82	1.55
Class B common stock
BASIC EARNINGS PER SHARE:
Basic earnings per share	0.70	0.55	1.84	1.57
DILUTED EARNINGS PER SHARE:
Diluted earnings per share	$ 0.69	$ 0.55	$ 1.82	$ 1.55

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
NET INCOME	$ 27,937,000	$ 21,923,000	$ 73,269,000	$ 61,905,000
OTHER COMPREHENSIVE INCOME (LOSS):
Cumulative-effect adjustment for adoption of Accounting Standards Update 2018-02	0	0	(24,000)	0
Translation adjustments, net of tax	4,000	(27,000)	9,000	(54,000)
Total other comprehensive income (loss)	4,000	(27,000)	(15,000)	(54,000)
COMPREHENSIVE INCOME	$ 27,941,000	$ 21,896,000	$ 73,254,000	$ 61,851,000

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Changes in Stockholders' Equity Statement - USD ($)	Total	Common Stock, Class A	Common Stock, Class B	Additional Paid-In Capital	Treasury Stock, at cost	Retained Earnings	Accumulated Other Comprehensive Loss
At beginning of period at Dec. 31, 2017		$ 263,000	$ 132,000	$ 492,030,000	$ (9,158,000)	$ 860,027,000	$ (320,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock option exercises		4,000		11,489,000
Stock-based compensation expense	$ 3,583,000	1,000		3,582,000
Payment consideration to tax authority on employees' behalf				(2,723,000)
Net income	61,905,000					61,905,000
Dividends						(29,687,000)
Cumulative-effect adjustment for adoption of Accounting Standards Update 2018-02	0					0
Cumulative-effect adjustment for adoption of Accounting Standards Update 2014-09						587,000
Translation adjustments, net of tax	(54,000)						(54,000)
At end of period at Sep. 30, 2018	1,388,078,000	268,000	132,000	504,378,000	(9,158,000)	892,832,000	(374,000)
At beginning of period at Jun. 30, 2018		266,000	132,000	498,370,000	(9,158,000)	880,837,000	(347,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock option exercises		2,000		4,667,000
Stock-based compensation expense		0		1,341,000
Payment consideration to tax authority on employees' behalf				0
Net income	21,923,000					21,923,000
Dividends						(9,928,000)
Cumulative-effect adjustment for adoption of Accounting Standards Update 2018-02	0					0
Cumulative-effect adjustment for adoption of Accounting Standards Update 2014-09						0
Translation adjustments, net of tax	(27,000)						(27,000)
At end of period at Sep. 30, 2018	1,388,078,000	268,000	132,000	504,378,000	(9,158,000)	892,832,000	(374,000)
At beginning of period at Dec. 31, 2018	1,401,194,000	268,000	132,000	506,970,000	(9,158,000)	903,084,000	(102,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock option exercises		2,000		9,154,000
Stock-based compensation expense	5,188,000	1,000		5,187,000
Payment consideration to tax authority on employees' behalf				(1,476,000)
Net income	73,269,000					73,269,000
Dividends						(32,360,000)
Cumulative-effect adjustment for adoption of Accounting Standards Update 2018-02	(24,000)					(24,000)
Cumulative-effect adjustment for adoption of Accounting Standards Update 2014-09						0
Translation adjustments, net of tax	9,000						9,000
At end of period at Sep. 30, 2019	1,454,956,000	271,000	132,000	519,835,000	(9,158,000)	943,969,000	(93,000)
At beginning of period at Jun. 30, 2019		270,000	132,000	513,840,000	(9,158,000)	926,855,000	(97,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock option exercises		1,000		4,176,000
Stock-based compensation expense		0		1,938,000
Payment consideration to tax authority on employees' behalf				(119,000)
Net income	27,937,000					27,937,000
Dividends						(10,823,000)
Cumulative-effect adjustment for adoption of Accounting Standards Update 2018-02	0					0
Cumulative-effect adjustment for adoption of Accounting Standards Update 2014-09						0
Translation adjustments, net of tax	4,000						4,000
At end of period at Sep. 30, 2019	$ 1,454,956,000	$ 271,000	$ 132,000	$ 519,835,000	$ (9,158,000)	$ 943,969,000	$ (93,000)

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows - USD ($)	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
CASH FLOWS FROM (USED IN) OPERATING ACTIVITIES:
Net income	$ 73,269,000	$ 61,905,000
Adjustments to reconcile net income to net cash flow from (used in) operating activities:
Depreciation and amortization	39,470,000	40,028,000
Noncash lease expense	20,949,000	0
Deferred income taxes	9,773,000	13,274,000
Stock-based compensation expense	5,188,000	3,583,000
Contract loss reserve	(881,000)	0
Equity in (earnings) of unconsolidated subsidiaries	(4,000)	(27,000)
Change in assets and liabilities—net of effects from acquired businesses:
Receivables—net	60,182,000	(49,289,000)
Prepaid expenses	(5,609,000)	(8,448,000)
Other current assets	(1,067,000)	14,356,000
Employee supplemental savings plan asset	(4,396,000)	(1,899,000)
Accounts payable and accrued expenses	28,888,000	4,946,000
Accrued salaries and related expenses	9,830,000	5,907,000
Contract liabilities	15,682,000	10,256,000
Operating lease liabilities	(21,077,000)	0
Accrued retirement	2,655,000	965,000
Other	107,000	(1,343,000)
Net cash flow from operating activities	232,959,000	94,214,000
CASH FLOWS FROM (USED IN) INVESTING ACTIVITIES:
Acquisition of a business-net of cash acquired	(153,180,000)	(5,279,000)
Purchases of property and equipment	(38,455,000)	(25,029,000)
Deferred contract costs	(3,520,000)	(3,586,000)
Investment in capitalized software for internal use	(2,784,000)	(4,199,000)
Proceeds from equity method investment	283,000	0
Proceeds from corporate owned life insurance	0	1,300,000
Net cash used in investing activities	(197,656,000)	(36,793,000)
CASH FLOWS FROM (USED IN) FINANCING ACTIVITIES:
Borrowing under revolving credit facility	465,500,000	501,000,000
Repayments under revolving credit facility	(448,000,000)	(532,000,000)
Dividends paid	(32,365,000)	(29,691,000)
Proceeds from exercise of stock options	9,156,000	11,493,000
Payment consideration to tax authority on employees' behalf	(1,476,000)	(2,723,000)
Principal paid on financing leases	(99,000)	0
Net cash used in financing activities	(7,284,000)	(51,921,000)
NET CHANGE IN CASH AND CASH EQUIVALENTS	28,019,000	5,500,000
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	5,294,000	9,451,000
CASH AND CASH EQUIVALENTS, END OF PERIOD	33,313,000	14,951,000
SUPPLEMENTAL CASH FLOW INFORMATION
Cash paid for interest	1,938,000	1,961,000
Cash paid for income taxes, net of refunds	16,117,000	(6,750,000)
Noncash investing and financing activities:
Operating lease liabilities arising from obtaining right of use assets	18,527,000	0
Finance lease liabilities arising from obtaining right of use assets	368,000	0
Capital expenditures incurred but not yet paid	$ 1,333,000	$ 112,000

Description of the Business (No

Description of the Business (Notes)	9 Months Ended
	Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of the Business [Text Block]	Description of the Business

Basis of Presentation (Notes)

Basis of Presentation (Notes)	9 Months Ended
	Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation [Text Block]	Basis of Presentation The accompanying condensed consolidated financial statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (SEC). Certain information and note disclosures normally included in the annual financial statements, prepared in accordance with accounting principles generally accepted in the U.S., have been condensed or omitted pursuant to those rules and regulations. The preparation of these condensed consolidated financial statements requires management to make estimates and judgments that affect the reported amounts of assets, liabilities, revenue and expenses. We recommend that you read these condensed consolidated financial statements in conjunction with the audited consolidated financial statements and related notes included in our Annual Report on Form 10-K for the fiscal year ended December 31, 2018 , previously filed with the SEC. We believe that the condensed consolidated financial statements in this Form 10-Q reflect all adjustments that are necessary to fairly present the financial position, results of operations and cash flows for the interim periods presented. The results of operations for such interim periods are not necessarily indicative of the results that can be expected for the full year.

Revenue from Contracts with Cus

Revenue from Contracts with Customers (Notes)	9 Months Ended
	Sep. 30, 2019
Revenue from Contract with Customer [Abstract]
Revenue from Contracts with Customer [Text Block]	Revenue from Contracts with Customers On January 1, 2018, we adopted Accounting Standards Codification (ASC) 606, Revenue from Contracts with Customers, using the modified retrospective method applied to those contracts that were not substantially complete as of January 1, 2018. ASC 606 outlines a five-step model whereby revenue is recognized as performance obligations within the contract are satisfied. ASC 606 also requires new, expanded disclosures regarding revenue recognition. We recognized the cumulative effect of adopting ASC 606 as an increase to the 2018 opening balance of retained earnings in the amount of $0.8 million , with the impact primarily related to fixed-price contracts. We derive revenue from contracts with customers primarily from contracts with the U.S. government in the areas of defense, intelligence, homeland security and other federal civilian agencies. Substantially all of our revenue is derived from services and solutions provided to the U.S. government or to prime contractors supporting the U.S. government, including services by our employees and our subcontractors, and solutions that include third-party hardware and software that we purchase and integrate as a part of our overall solutions. Customer requirements may vary from period-to-period depending on specific contract and customer requirements. We provide our services and solutions under three types of contracts: cost-reimbursable, fixed-price and time-and-materials. Under cost-reimbursable contracts, we are reimbursed for costs that are determined to be reasonable, allowable and allocable to the contract and paid a fee representing the profit margin negotiated between us and the contracting agency, which may be fixed or performance based. Under fixed-price contracts, we perform specific tasks for a fixed price. Fixed-price contracts may include either a product delivery or specific service performance over a defined period. Under time-and-materials contracts, we are reimbursed for labor at fixed hourly rates and are generally reimbursed separately for allowable materials and expenses at cost. We typically recognize revenue for time and material contracts under the "right to invoice" model. For contracts that do not meet the criteria to measure performance as a right to invoice under the series guidance, we utilize an Estimate at Completion process to measure progress toward completion. We typically estimate progress towards completion based on cost incurred or direct labor incurred. As part of this process, we review information including, but not limited to, any outstanding key contract matters, progress towards completion and the related program schedule, identified risks and opportunities and the related changes in estimates of revenue and costs. The risks and opportunities include judgments about the ability and cost to achieve the contract milestones and other technical contract requirements. We make assumptions and estimates regarding labor productivity and availability, the complexity of the work to be performed, the availability of materials, the length of time to complete the performance obligation, execution by our subcontractors, the availability and timing of funding from our customer and overhead cost rates, among other variables. A significant change in one or more of these estimates could affect the timing in which we recognize revenue on our contracts. For the three months ended September 30, 2019 and 2018 , the aggregate impact of adjustments in contract estimates increased our revenue by $5.9 million and $4.5 million , respectively. For the nine months ended September 30, 2019 and 2018 , the aggregate impact of adjustments in contract estimates increased our revenue by $9.0 million and $8.8 million , respectively. We have one reportable segment. Our U.S. government customers typically exercise independent decision-making and contracting authority. Offices or divisions within an agency or department of the U.S. government may directly, or through a prime contractor, use our services as a separate customer as long as the customer has independent decision-making and contracting authority within its organization. We treat sales to U.S. government customers as sales within the U.S. regardless of where the services are performed. The following tables disclose revenue (in thousands) by contract type, customer, prime or subcontractor and geography for the periods presented. Three months ended Nine months ended 2019 2018 2019 2018 Cost-reimbursable $ 397,921 $ 337,105 $ 1,129,538 $ 970,647 Fixed-price 120,632 108,921 323,723 341,854 Time-and-materials 60,626 51,179 164,885 148,984 Revenue $ 579,179 $ 497,205 $ 1,618,146 $ 1,461,485 Three months ended Nine months ended 2019 2018 2019 2018 Department of Defense and intelligence agencies $ 443,253 $ 365,044 $ 1,241,609 $ 1,055,911 Federal civilian agencies 124,243 121,543 341,880 371,767 State agencies, international agencies and commercial entities 11,683 10,618 34,657 33,807 Revenue $ 579,179 $ 497,205 $ 1,618,146 $ 1,461,485 Three months ended Nine months ended 2019 2018 2019 2018 Prime contractor $ 524,370 $ 442,413 $ 1,448,875 $ 1,298,437 Subcontractor 54,809 54,792 169,271 163,048 Revenue $ 579,179 $ 497,205 $ 1,618,146 $ 1,461,485 Three months ended Nine months ended 2019 2018 2019 2018 U.S. $ 571,923 $ 490,098 $ 1,596,365 $ 1,439,293 International 7,257 7,107 21,781 22,192 Revenue $ 579,179 $ 497,205 $ 1,618,146 $ 1,461,485 The following table discloses contract receivables (in thousands): September 30, 2019 December 31, 2018 Billed receivables $ 292,323 $ 301,716 Unbilled receivables 82,054 109,895 Allowance for doubtful accounts (7,335 ) (6,233 ) Receivables—net $ 367,042 $ 405,378 Receivables at September 30, 2019 are expected to be substantially collected within one year except for approximately $1.1 million , of which 100% is related to receivables from sales to the U.S. government or from contracts in which we acted as a subcontractor to other contractors selling to the U.S. government. We do not believe that we have significant exposure to credit risk as billed receivables and unbilled receivables are primarily due from the U.S. government. The allowance for doubtful accounts represents our estimate for exposure due to compliance, contractual issues and bad debts related to prime contractors. The following table discloses contract liabilities (in thousands): September 30, 2019 December 31, 2018 Contract liabilities $ 43,891 $ 28,209 For the three months ended and nine months ended September 30, 2019 , the amount of revenue that was included in the opening contract liabilities balance were $0.9 million and $23.4 million , respectively. The remaining performance obligation as of September 30, 2019 is $3.1 billion . The following table discloses when we expect to recognize the remaining performance obligation as revenue (in billions): For the remaining three months ending December 31, 2019 For the year ending December 31, 2020 December 31, 2021 Thereafter $ 0.6 $ 1.5 $ 0.5 $ 0.5

Leases (Notes)

Leases (Notes)	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
Lease Disclosure [Text Block]	Leases We adopted ASC 842, Leases , on January 1, 2019. We elected to apply the provisions of the standard as of the date of adoption, and, therefore, have not restated prior comparative periods. Upon adoption, we recorded operating lease liabilities of $129.6 million and operating lease right of use (ROU) assets of $118.7 million . We elected the practical expedient to recognize the lease payments related to short-term leases as profit or loss on a straight-line basis over the lease term and variable lease payments in the period in which the obligation for those payments are incurred. We also elected the following transition related practical expedients: not to reassess whether expired or existing contracts are or contain leases, not to reassess lease classification as determined under ASC 840 and not to reassess initial direct costs from any existing lease. We elected the practical expedient as an accounting election not to separate nonlease components from lease components on all classes of underlying assets. Our leases include nonlease components such as common area maintenance (CAM), utilities and operating expenses. Additionally, we implemented internal controls and key system functionality to enable the preparation of financial information upon adoption. ASC 842 had a material impact on our condensed consolidated balance sheet, but did not have an impact on our condensed consolidated income statement. The most significant impact was the recognition of ROU assets and lease liabilities for operating leases, while our accounting for finance leases remained substantially unchanged. We determine if a contract is or contains a lease at inception. A contract is or contains a lease if the contract conveys the right to control the use of identified property or equipment (an identified asset) for a period of time in exchange for consideration. We have the right to control the use of the identified asset when we have both of the following: the right to obtain substantially all of the economic benefits from use of the identified asset and the right to direct the use of the identified asset. In making this determination, we consider all relevant facts and circumstances. We reassess whether a contract is or contains a lease only if the terms and conditions of the contract are changed. We account for lease components and nonlease components associated with a lease as a single lease component. Our ROU asset is recognized as the lease liability, any initial indirect costs and any prepaid lease payments, less any lease incentives. Our lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at commencement date. Our lease payments consist of amounts relating to the use of the underlying asset during the lease term, specifically fixed payments, payment to be made in optional periods when we are reasonably certain to exercise an option to extend the lease or not to exercise an option to terminate the lease and the amounts probable of being owned by us under residual guarantees. Our variable lease payments are excluded in measuring ROU assets and lease liabilities because they do not depend on an index or a rate or are not in substance fixed payments. We exclude lease incentives and initial direct costs incurred from our lease payments. Our leases typically do not provide an implicit rate, we use our incremental borrowing rate based on the information available at the commencement date in determining the present value of future payments. Our operating leases are primarily made up of real estate. Our variable lease payments do not depend on an index or a rate or are not in substance fixed payments. Our leases have remaining lease terms of 1 day to 11 years , some of which include options to extend the leases for up to 14 years , and some of which include options to terminate the leases within 1 year . Our transportation vehicles and equipment leases include a residual value guarantee, which is a guarantee made to the lessor that the value of the underlying asset returned to the lessor at the end of the lease will be at least a specific amount. We sublease some of our real estate space. Sublease income is immaterial and is presented net with the corresponding lease expense. We do not have any leases that have not yet commenced due to construction or design of the underlying asset. We recognize payments related to short-term leases (less than one year) as expense on a straight-line basis over the lease term and variable lease payments in the period in which the obligation for those payments were incurred. As such, our short-term lease expense for the three and nine months ended September 30, 2019 was $1.4 million and $4.2 million , respectively. For the three and nine months ended September 30, 2019 , we incurred variable lease costs of $0.5 million and $1.9 million , respectively. In our condensed consolidated statement of income, we recognize lease expense within general and administrative expense or cost of goods sold depending on the use of the underlying lease. For leases classified as financing, the interest on lease liabilities is classified within interest expense. The balance sheet information related to our leases was as follows (dollars in thousands): September 30, 2019 Operating Leases Operating lease right of use assets $ 116,236 Operating lease liabilities—current $ 28,170 Operating lease liabilities—long term 98,979 Total operating lease liabilities $ 127,149 Finance Leases Property and equipment—gross $ 669 Accumulated depreciation (194 ) Property and equipment—net $ 475 Accounts payable and other accrued expenses $ 143 Other long-term liabilities 332 Total finance lease liabilities $ 475 The components of lease expense were as follows (in thousands): Three months ended Nine months ended Operating lease expenses $ 8,412 $ 24,727 Depreciation of right of use assets $ 45 $ 194 Interest on lease liabilities 19 33 Finance lease expenses $ 64 $ 227 The weighted average information related to leases was as follows: September 30, 2019 Weighted Average Remaining Lease Term Operating leases 5 years Finance leases 3 years Weighted Average Discount Rate Operating leases 3 % Finance leases 5 % Future minimum lease payments under non-cancellable leases as of September 30, 2019 were as follows (in thousands): Operating Leases Financing Leases For the three months ended December 31, 2019 $ 6,437 $ 31 2020 33,859 176 2021 31,033 156 2022 27,272 150 2023 22,666 41 Thereafter 16,759 — Total future minimum lease payments 138,026 554 Less imputed interest (10,877 ) (79 ) Total $ 127,149 $ 475

Acquisitions (Notes)

Acquisitions (Notes)	9 Months Ended
	Sep. 30, 2019
Business Combinations [Abstract]
Business Combination Disclosure [Text Block]	Acquisitions H2M Group (H2M) —On August 8, 2019 , we completed the acquisition of H2M through a membership interest purchase agreement by and among H2M Group, HHM Holding LLC, and the Members and ManTech International Corporation. The results of H2M's operations have been included in our condensed consolidated financial statements since that date. We funded the acquisition with cash on hand and borrowings on our revolving credit facility. H2M is a provider of intelligence and analysis services and solutions primarily to the National Geospatial-Intelligence Agency (NGA). This acquisition strengthens our ability to help key government agencies implement new automation techniques that enable intelligence analysts to more effectively navigate large amounts of data and to distill the critical information that informs actionable intelligence necessary to make mission-critical decisions. For the nine months ended September 30, 2019 , we incurred approximately $0.3 million of acquisition costs related to the H2M transaction, which are included in general and administrative expenses in our condensed consolidated statement of income. The preliminary purchase price of $38.8 million , which includes an estimated working capital adjustment, was preliminarily allocated to the underlying assets and liabilities based on their estimated fair value at the date of acquisition. As we are still in the process of reviewing the fair value of the assets acquired and liabilities assumed and in finalizing the closing working capital adjustment, the purchase price allocation for H2M is not complete as of September 30, 2019 . Recognition of goodwill is largely attributed to the value paid for H2M's capabilities to support government agencies in the implementation of high-quality geospatial and professional services. The goodwill recorded for this transaction will be deductible for tax purposes over 15 years . In preliminarily allocating the purchase price, we considered, among other factors, analysis of historical performance and estimates of future performance of H2M's contracts. The components of other intangible assets associated with the acquisition were customer relationships and backlog valued at $9.6 million and $2.3 million , respectively. Customer contracts and related relationships represent the underlying relationships and agreements with H2M's existing customers. Customer relationships are amortized using the pattern of benefits method over their estimated useful lives of approximately 20 years . Backlog is amortized using the pattern of benefits method over its estimated useful life of 2 years . The weighted-average amortization period for the intangible assets is 17 years . The following table represents the preliminary purchase price allocation for H2M (in thousands): Cash and cash equivalents $ 15 Receivables 4,011 Prepaid expenses 199 Other current assets 2 Goodwill 25,382 Other intangible assets 11,900 Operating lease ROU asset 145 Property and equipment 57 Other assets 7 Accounts payable and accrued expenses (1,775 ) Accrued salaries and related expenses (1,000 ) Operating lease liabilities - current (86 ) Operating lease liabilities - non current (60 ) Net assets acquired and liabilities assumed $ 38,797 Kforce Government Solutions (KGS) —On April 1, 2019 , we completed the acquisition of KGS. KGS was a wholly owned subsidiary of the publicly traded commercial technology and staffing company KForce, Inc. The results of KGS's operations have been included in our condensed consolidated financial statements since that date. The acquisition was completed through an equity purchase agreement dated February 28, 2019 , by and among Kforce Government Solutions, Inc and other beneficiaries and ManTech International Corporation. We funded the acquisition with cash on hand and borrowings on our revolving credit facility. KGS provides services, IT solutions, transformation and management consulting and data analytics - most notably in the healthcare IT market. This acquisition will expand our presence with important customers such as the Department of Veteran Affairs (VA). For the nine months ended September 30, 2019 , we incurred approximately $1.0 million of acquisition costs related to the KGS transaction, which are included in general and administrative expenses in our condensed consolidated statement of income. The purchase price of $114.6 million , which includes the finalized working capital adjustment, was preliminarily allocated to the underlying assets and liabilities based on their estimated fair value at the date of acquisition. As we are still in the process of reviewing the fair value of the assets acquired and liabilities assumed, the purchase price allocation for KGS is not complete as of September 30, 2019 . Recognition of goodwill is largely attributed to the value paid for KGS's capabilities to support customers in IT solutions, transformation and management consulting and data analytics. A majority of the goodwill recorded will not be deductible for tax purposes. In preliminarily allocating the purchase price, we considered, among other factors, analysis of historical financial performance and estimates of future performance of KGS's contracts. The components of other intangible assets associated with the acquisition were customer relationships and backlog valued at $33.1 million and $1.6 million , respectively. Customer contracts and related relationships represent the underlying relationships and agreements with KGS's existing customers. Customer relationships are amortized using the pattern of benefits method over their estimated useful lives of approximately 20 years . Backlog is amortized straight-line over its estimated useful life of 1 year . The weighted-average amortization period for the intangible assets is 19 years . The following table represents the preliminary purchase price allocation for KGS (in thousands): Cash and cash equivalents $ 154 Receivables 17,835 Prepaid expenses 368 Other current assets 168 Goodwill 80,025 Other intangible assets 34,839 Property and equipment 361 Accounts payable and accrued expenses (6,887 ) Accrued salaries and related expenses (4,421 ) Deferred income taxes (7,319 ) Other long-term liabilities (571 ) Net assets acquired and liabilities assumed $ 114,552

Earnings Per Share (Notes)

Earnings Per Share (Notes)	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Earnings Per Share [Text Block]	Earnings Per Share Under ASC 260 , Earnings per Share , the two-class method is an earnings allocation formula that determines earnings per share for each class of common stock according to dividends declared (or accumulated) and participation rights in undistributed earnings. Under that method, basic and diluted earnings per share data are presented for each class of common stock. In applying the two-class method, we determined that undistributed earnings should be allocated equally on a per share basis between Class A and Class B common stock. Under our Certificate of Incorporation, the holders of the common stock are entitled to participate ratably, on a share-for-share basis as if all shares of common stock were of a single class, in such dividends as may be declared by the Board of Directors. During the nine months ended September 30, 2019 and 2018 , we declared and paid quarterly dividends in the amount of $0.27 per share and $0.25 per share, respectively, on both classes of common stock. Basic earnings per share has been computed by dividing net income available to common stockholders by the weighted average number of shares of common stock outstanding during each period. Shares issued during the period and shares reacquired during the period are weighted for the portion of the period in which the shares were outstanding. Diluted earnings per share have been computed in a manner consistent with that of basic earnings per share while giving effect to all potentially dilutive common shares that were outstanding during each period. The net income available to common stockholders and weighted average number of common shares outstanding used to compute basic and diluted earnings per share for each class of common stock are as follows (in thousands, except per share amounts): Three months ended Nine months ended 2019 2018 2019 2018 Distributed earnings $ 10,823 $ 9,928 $ 32,360 $ 29,687 Undistributed earnings 17,114 11,995 40,909 32,218 Net income $ 27,937 $ 21,923 $ 73,269 $ 61,905 Class A common stock: Basic net income available to common stockholders $ 18,729 $ 14,623 $ 49,048 $ 41,226 Basic weighted average common shares outstanding 26,822 26,421 26,706 26,293 Basic earnings per share $ 0.70 $ 0.55 $ 1.84 $ 1.57 Diluted net income available to common stockholders $ 18,798 $ 14,682 $ 49,203 $ 41,402 Effect of potential exercise of stock options 306 322 257 340 Diluted weighted average common shares outstanding 27,128 26,743 26,963 26,633 Diluted earnings per share $ 0.69 $ 0.55 $ 1.82 $ 1.55 Class B common stock: Basic net income available to common stockholders $ 9,208 $ 7,300 $ 24,221 $ 20,679 Basic weighted average common shares outstanding 13,188 13,189 13,188 13,189 Basic earnings per share $ 0.70 $ 0.55 $ 1.84 $ 1.57 Diluted net income available to common stockholders $ 9,139 $ 7,241 $ 24,066 $ 20,503 Diluted weighted average common shares outstanding 13,188 13,189 13,188 13,189 Diluted earnings per share $ 0.69 $ 0.55 $ 1.82 $ 1.55 For the three months ended September 30, 2019 and 2018 , options to purchase 7,641 shares and 242,789 shares, respectively, were outstanding but not included in the computation of diluted earnings per share because the options' effect would have been anti-dilutive. For the nine months ended September 30, 2019 and 2018 , options to purchase 331,994 shares and 268,013 shares, respectively, were outstanding but not included in the computation of diluted earnings per share because the options' effect would have been anti-dilutive. For the nine months ended September 30, 2019 and 2018 , there were 255,376 shares and 387,926 shares, respectively, issued from the exercise of stock options. For the nine months ended September 30, 2019 and 2018 there were 76,346 shares and 86,233 shares, respectively, issued from the vesting of restricted stock units.

Property and Equipment (Notes)

Property and Equipment (Notes)	9 Months Ended
	Sep. 30, 2019
Property, Plant and Equipment [Abstract]
Property and Equipment [Text Block]	Property and Equipment Major classes of property and equipment are summarized as follows (in thousands): September 30, December 31, Furniture and equipment $ 131,114 $ 97,577 Leasehold improvements 48,421 43,065 Finance leases 669 — Property and equipment—gross 180,204 140,642 Accumulated depreciation and amortization (107,211 ) (89,215 ) Property and equipment—net $ 72,993 $ 51,427 Depreciation and amortization expense related to property and equipment for the three months ended September 30, 2019 and 2018 was $6.9 million and $6.4 million , respectively. Depreciation and amortization expense related to property and equipment for the nine months ended September 30, 2019 and 2018 was $19.4 million and $19.1 million , respectively.

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets (Notes)	9 Months Ended
	Sep. 30, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets [Text Block]	Goodwill and Other Intangible Assets The change in the carrying amount of goodwill during the year ended December 31, 2018 and nine months ended September 30, 2019 are as follows (in thousands): Goodwill Balance Goodwill at December 31, 2017 $ 1,084,560 Acquisition fair value adjustment 1,246 Goodwill at December 31, 2018 1,085,806 Acquisitions 105,407 Goodwill at September 30, 2019 $ 1,191,213 Other intangible assets consisted of the following (in thousands): September 30, 2019 December 31, 2018 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Other intangible assets: Contract and program intangible assets $ 402,532 $ 215,942 $ 186,590 $ 355,932 $ 201,298 $ 154,634 Capitalized software cost for internal use 53,322 36,665 16,657 50,925 33,597 17,328 Total other intangible assets—net $ 455,854 $ 252,607 $ 203,247 $ 406,857 $ 234,895 $ 171,962 Amortization expense relating to intangible assets for the three months ended September 30, 2019 and 2018 was $6.1 million and $6.8 million , respectively. Amortization expense relating to intangible assets for the nine months ended September 30, 2019 and 2018 was $18.0 million and $20.3 million , respectively. We estimate that we will have the following amortization expense for the future periods indicated below (in thousands): For the remaining three months ending December 31, 2019 $ 6,710 For the year ending: December 31, 2020 $ 25,301 December 31, 2021 $ 23,072 December 31, 2022 $ 20,139 December 31, 2023 $ 16,858 December 31, 2024 $ 15,151

Debt (Notes)

Debt (Notes)	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
Debt [Text Block]	Debt Revolving Credit Facility —We maintain a credit facility with a syndicate of lenders led by Bank of America, N.A., as sole administrative agent. The credit agreement provides for a $500 million revolving credit facility, with a $75 million letter of credit sublimit and a $30 million swing line loan sublimit. The credit agreement also includes an accordion feature that permits us to arrange with the lenders for the provision of additional commitments. The maturity date is August 17, 2022 . Borrowings under our credit agreement are collateralized by substantially all of our assets and those of our Material Subsidiaries (as defined in the credit agreement) and bear interest at one of the following variable rates as selected by us at the time of borrowing: a London Interbank Offer Rate base rate plus market-rate spreads ( 1.25% to 2.25% based on our consolidated total leverage ratio) or Bank of America's base rate plus market spreads ( 0.25% to 1.25% based on our consolidated total leverage ratio). The terms of the credit agreement permit prepayment and termination of the loan commitments at any time, subject to certain conditions. The credit agreement requires us to comply with specified financial covenants, including the maintenance of certain leverage ratios and a consolidated coverage ratio. The credit agreement also contains various covenants, including affirmative covenants with respect to certain reporting requirements and maintaining certain business activities, and negative covenants that, among other things, may limit or impose restrictions on our ability to incur liens, incur additional indebtedness, make investments, make acquisitions and undertake certain other actions. As of and during the nine months ended September 30, 2019 and 2018 , we were in compliance with the financial covenants under the credit agreement. There was $25.0 million and $7.5 million outstanding on our revolving credit facility at September 30, 2019 and December 31, 2018 , respectively. The maximum available borrowing under the revolving credit facility at September 30, 2019 was $467.3 million . As of September 30, 2019 , we were contingently liable under letters of credit totaling $7.7 million

Commitments and Contingencies (

Commitments and Contingencies (Notes)	9 Months Ended
	Sep. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies [Text Block]	Commitments and Contingencies Contracts with the U.S. government, including subcontracts, are subject to extensive legal and regulatory requirements and, from time-to-time, agencies of the U.S. government, in the ordinary course of business, investigate whether our operations are conducted in accordance with these requirements and the terms of the relevant contracts. U.S. government investigations of us, whether related to our U.S. government contracts or conducted for other reasons, could result in administrative, civil or criminal liabilities, including repayments, fines or penalties being imposed upon us, or could lead to suspension or debarment from future U.S. government contracting activities. Management believes it has adequately reserved for any losses that may be experienced from any investigation of which it is aware. The Defense Contract Audit Agency has substantially completed our incurred cost audits through 2016 with no material adjustments. The remaining audits for 2017 through 2018 are not expected to have a material effect on our financial position, results of operations or cash flow and management believes it has adequately reserved for any losses. In the normal course of business, we are involved in certain governmental and legal proceedings, claims and disputes and have litigation pending under several suits. Current legal matters are individually immaterial and we believe that the ultimate resolution of these items will not have a material effect on our financial position, results of operations or cash flows. Management believes it has adequately reserved for any losses that may be experienced from legal proceedings, claims and disputes and pending litigations of which it is aware. An officer of our Company was party to an arbitration proceeding with a former employer relating to a breach of a contract claim. Pursuant to indemnification arrangements we have with this officer, we were exposed to a loss related to this claim. In the period ending September 30, 2019 , we settled the claim. The settlement amount was not material to our condensed consolidated financial statements. We have $7.7 million outstanding on our letter of credit, of which $7.6 million is related to an outstanding performance bond in connection with a contract between ManTech MENA, LLC and Jadwalean International Operations and Management Company to fulfill technical support requirements for the Royal Saudi Air Force.

Stock-Based Compensation (Notes

Stock-Based Compensation (Notes)	9 Months Ended
	Sep. 30, 2019
Share-based Payment Arrangement, Noncash Expense [Abstract]
Stock-Based Compensation [Text Block]	Stock-Based Compensation Our 2016 Management Incentive Plan (the Plan) was designed to attract, retain and motivate key employees. The types of awards available under the Plan include, among others, stock options, restricted stock and restricted stock units (RSUs). Equity awards granted under the Plan are settled in shares of Class A common stock. At the beginning of each year, the Plan provides that the number of shares available for issuance automatically increases by an amount equal to 1.5% of the total number of shares of Class A and Class B common stock outstanding on December 31 st of the previous year. On January 2, 2019 , there were 596,422 additional shares made available for issuance under the Plan. Through September 30, 2019 , the Board of Directors has authorized the issuance of up to 15,148,321 shares under this Plan. Through September 30, 2019 , the remaining aggregate number of shares of our common stock available for future grants under the Plan was 6,727,002 . The Plan expires in March 2026 . The Plan is administered by the compensation committee of our Board of Directors, along with its delegates. Subject to the express provisions of the Plan, the committee has the Board of Directors’ authority to administer and interpret the Plan, including the discretion to determine the exercise price, vesting schedule, contractual life and the number of shares to be issued. Stock Compensation Expense —For the three months ended September 30, 2019 and 2018 , we recorded $2.0 million and $1.3 million of stock-based compensation expense. For the nine months ended September 30, 2019 and 2018 , we recorded $5.2 million and $3.6 million of stock-based compensation expense. No compensation expense of employees with stock awards, including stock-based compensation expense, was capitalized during the periods. For the three months ended September 30, 2019 and 2018 , we recorded $(0.9) million and $(1.2) million , respectively, to income tax expense (benefit) related to the exercise of stock options, vested cancellations and the vesting of restricted stock and restricted stock units. For the nine months ended September 30, 2019 and 2018 , we recorded $(1.6) million and $(2.9) million , respectively, to income tax expense (benefit) related to the exercise of stock options, vested cancellations and the vesting of restricted stock and restricted stock units. Stock Options —Under the Plan, we have issued stock options. A stock option gives the holder the right, but not the obligation to purchase a certain number of shares at a predetermined price for a specific period of time. We typically issue options that vest over three years in equal installments beginning on the first anniversary of the date of grant. Under the terms of the Plan, the contractual life of the option grants may not exceed eight years . During the nine months ended September 30, 2019 and 2018 , we issued options that expire five years from the date of grant. Fair Value Determination —We have used the Black-Scholes-Merton option pricing model to determine the fair value of our awards on the date of grant. We will reconsider the use of the Black-Scholes-Merton model if additional information becomes available in the future that indicates another model would be more appropriate or if grants issued in future periods have characteristics that cannot be reasonably estimated under this model. The following weighted-average assumptions were used for option grants during the nine months ended September 30, 2019 and 2018 : • Volatility —The expected volatility of the options granted was estimated based upon historical volatility of our share price through weekly observations of our trading history. • Expected life of options —The expected life of options granted to employees was determined from historical exercises of the grantee population. The options had graded vesting over three years in equal installments beginning on the first anniversary of the date of grant and a contractual term of five years . • Risk-free interest rate —The yield on zero-coupon U.S. Treasury strips was used to extrapolate a forward-yield curve. This “term structure” of future interest rates was then input into a numeric model to provide the equivalent risk-free rate to be used in the Black-Scholes-Merton model based on the expected term of the underlying grants. • Dividend Yield —The Black-Scholes-Merton valuation model requires an expected dividend yield as an input. We have calculated our expected dividend yield based on an expected annual cash dividend of $1.08 per share. The following table summarizes weighted-average assumptions used in our calculations of fair value for the nine months ended September 30, 2019 and 2018 : Nine months ended 2019 2018 Volatility 27.00 % 26.34 % Expected life of options 3 years 3 years Risk-free interest rate 2.38 % 2.46 % Dividend yield 2.00 % 2.00 % Stock Option Activity —The weighted-average fair value of options granted during the nine months ended September 30, 2019 and 2018 , as determined under the Black-Scholes-Merton valuation model, was $10.10 and $9.98 , respectively. Option grants that vested during the nine months ended September 30, 2019 and 2018 had a combined fair value of $1.2 million and $0.7 million , respectively. The following table summarizes stock option activity for the year ended December 31, 2018 and the nine months ended September 30, 2019 : Number of Shares Weighted Average Exercise Price Aggregate Intrinsic Value Weighted Average Remaining Contractual Life Stock options outstanding at December 31, 2017 1,169,408 $ 35.88 $ 16,731 Granted 466,828 $ 54.87 Exercised (420,524 ) $ 30.05 $ 12,411 Cancelled and expired (122,312 ) $ 43.85 Stock options outstanding at December 31, 2018 1,093,400 $ 45.34 $ 8,776 Granted 256,006 $ 53.81 Exercised (255,376 ) $ 35.82 $ 7,038 Cancelled and expired (97,005 ) $ 50.89 Stock options outstanding at September 30, 2019 997,025 $ 49.42 $ 21,927 3 years Stock options exercisable at September 30, 2019 221,597 $ 41.09 $ 6,719 2 years The following table summarizes non-vested stock options for the nine months ended September 30, 2019 : Number of Shares Weighted Average Fair Value Non-vested stock options at December 31, 2018 774,402 $ 8.77 Granted 256,006 $ 10.10 Vested (161,114 ) $ 7.38 Cancelled (93,866 ) $ 9.23 Non-vested stock options at September 30, 2019 775,428 $ 9.44 Unrecognized compensation expense related to non-vested awards was $5.1 million as of September 30, 2019 , which is expected to be recognized over a weighted-average period of 2 years . Restricted Stock —Under the Plan, we have issued restricted stock. A restricted stock award is an issuance of shares that cannot be sold or transferred by the recipient until the vesting period lapses. Restricted stock issued to members of our Board of Directors vest on the one year anniversary of the grant date. The related compensation expense is recognized over the service period and is based on the grant date fair value of the stock. The grant date fair value of the restricted stock is equal to the closing market price of our common stock on the date of grant. Restricted Stock Activity — The following table summarizes the restricted stock activity during the year ended December 31, 2018 and the nine months ended September 30, 2019 . Number of Shares Weighted Average Fair Value Non-vested restricted stock at December 31, 2017 24,000 $ 37.90 Granted 24,000 $ 52.83 Vested (28,000 ) $ 40.03 Non-vested restricted stock at December 31, 2018 20,000 $ 52.83 Granted 24,000 $ 62.66 Vested (20,000 ) $ 52.83 Non-vested restricted stock at September 30, 2019 24,000 $ 62.66 RSUs —Under the Plan, we have issued restricted stock units (RSUs). RSUs are not actual shares, but rather a right to receive shares in the future. The shares are not issued and the employee cannot sell or transfer shares prior to vesting and have no voting rights until the RSUs vest. Employees who are granted RSUs do not receive dividend payments during the vesting period. Our employees have been granted performance-based RSUs and time-based RSUs. Performance-based RSUs result in the delivery of shares only if (a) performance criteria is met and (b) the employee remains employed, in good standing, through the date of the performance period. Time-based RSUs vest in one-third increments on the first, second and third anniversaries of the date of grant. The grant date fair value of the RSUs is equal to the closing market price of our common stock on the grant date less the present value of dividends expected to be awarded during the service period. We recognize the grant date fair value of RSUs of shares we expect to issue as compensation expense ratably over the requisite service period. RSU Activity —For performance-based RSUs that vested in 2019 and 2018 , each RSU awarded resulted in the issuance of 1.5 shares, which were issued net of applicable payroll tax withholdings. The following table summarizes the non-vested RSU activity during the year ended December 31, 2018 and the nine months ended September 30, 2019 : Number of Units Weighted Average Fair Value Non-vested RSUs at December 31, 2017 161,343 $ 31.36 Granted 76,713 $ 53.97 Vested (87,200 ) $ 28.40 Forfeited (13,260 ) $ 38.98 Non-vested RSUs at December 31, 2018 137,596 $ 45.11 Granted 99,675 $ 53.27 Vested (59,452 ) $ 42.46 Forfeited (10,677 ) $ 51.88 Non-vested RSUs at September 30, 2019 167,142 $ 50.48

Leases (Policies)

Leases (Policies)	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
Lessee, Leases [Policy Text Block]	We determine if a contract is or contains a lease at inception. A contract is or contains a lease if the contract conveys the right to control the use of identified property or equipment (an identified asset) for a period of time in exchange for consideration. We have the right to control the use of the identified asset when we have both of the following: the right to obtain substantially all of the economic benefits from use of the identified asset and the right to direct the use of the identified asset. In making this determination, we consider all relevant facts and circumstances. We reassess whether a contract is or contains a lease only if the terms and conditions of the contract are changed. We account for lease components and nonlease components associated with a lease as a single lease component. Our ROU asset is recognized as the lease liability, any initial indirect costs and any prepaid lease payments, less any lease incentives. Our lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at commencement date. Our lease payments consist of amounts relating to the use of the underlying asset during the lease term, specifically fixed payments, payment to be made in optional periods when we are reasonably certain to exercise an option to extend the lease or not to exercise an option to terminate the lease and the amounts probable of being owned by us under residual guarantees. Our variable lease payments are excluded in measuring ROU assets and lease liabilities because they do not depend on an index or a rate or are not in substance fixed payments. We exclude lease incentives and initial direct costs incurred from our lease payments. Our leases typically do not provide an implicit rate, we use our incremental borrowing rate based on the information available at the commencement date in determining the present value of future payments.

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Tables)	9 Months Ended
	Sep. 30, 2019
Revenue from Contract with Customer [Abstract]
Revenue by Contract Type [Table Text Block]	Three months ended Nine months ended 2019 2018 2019 2018 Cost-reimbursable $ 397,921 $ 337,105 $ 1,129,538 $ 970,647 Fixed-price 120,632 108,921 323,723 341,854 Time-and-materials 60,626 51,179 164,885 148,984 Revenue $ 579,179 $ 497,205 $ 1,618,146 $ 1,461,485
Revenue by Customer [Table Text Block]	Three months ended Nine months ended 2019 2018 2019 2018 Department of Defense and intelligence agencies $ 443,253 $ 365,044 $ 1,241,609 $ 1,055,911 Federal civilian agencies 124,243 121,543 341,880 371,767 State agencies, international agencies and commercial entities 11,683 10,618 34,657 33,807 Revenue $ 579,179 $ 497,205 $ 1,618,146 $ 1,461,485
Revenue by Contractor Type [Table Text Block]	Three months ended Nine months ended 2019 2018 2019 2018 Prime contractor $ 524,370 $ 442,413 $ 1,448,875 $ 1,298,437 Subcontractor 54,809 54,792 169,271 163,048 Revenue $ 579,179 $ 497,205 $ 1,618,146 $ 1,461,485
Revenue from External Customers by Geographic Areas [Table Text Block]	Three months ended Nine months ended 2019 2018 2019 2018 U.S. $ 571,923 $ 490,098 $ 1,596,365 $ 1,439,293 International 7,257 7,107 21,781 22,192 Revenue $ 579,179 $ 497,205 $ 1,618,146 $ 1,461,485
Schedule Of Contract Receivables [Table Text Block]	The following table discloses contract receivables (in thousands): September 30, 2019 December 31, 2018 Billed receivables $ 292,323 $ 301,716 Unbilled receivables 82,054 109,895 Allowance for doubtful accounts (7,335 ) (6,233 ) Receivables—net $ 367,042 $ 405,378
Contract with Customer, Asset and Liability [Table Text Block]	The following table discloses contract liabilities (in thousands): September 30, 2019 December 31, 2018 Contract liabilities $ 43,891 $ 28,209
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table Text Block]	The following table discloses when we expect to recognize the remaining performance obligation as revenue (in billions): For the remaining three months ending December 31, 2019 For the year ending December 31, 2020 December 31, 2021 Thereafter $ 0.6 $ 1.5 $ 0.5 $ 0.5

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
Lessee, Lease, Balance Sheet [Table Text Block]	The balance sheet information related to our leases was as follows (dollars in thousands): September 30, 2019 Operating Leases Operating lease right of use assets $ 116,236 Operating lease liabilities—current $ 28,170 Operating lease liabilities—long term 98,979 Total operating lease liabilities $ 127,149 Finance Leases Property and equipment—gross $ 669 Accumulated depreciation (194 ) Property and equipment—net $ 475 Accounts payable and other accrued expenses $ 143 Other long-term liabilities 332 Total finance lease liabilities $ 475
Lease, Cost [Table Text Block]	The components of lease expense were as follows (in thousands): Three months ended Nine months ended Operating lease expenses $ 8,412 $ 24,727 Depreciation of right of use assets $ 45 $ 194 Interest on lease liabilities 19 33 Finance lease expenses $ 64 $ 227
Lease Weighted Average Information [Table Text Block]	The weighted average information related to leases was as follows: September 30, 2019 Weighted Average Remaining Lease Term Operating leases 5 years Finance leases 3 years Weighted Average Discount Rate Operating leases 3 % Finance leases 5 %
Schedule of Maturities of Lease Liabilities [Table Text Block]	Future minimum lease payments under non-cancellable leases as of September 30, 2019 were as follows (in thousands): Operating Leases Financing Leases For the three months ended December 31, 2019 $ 6,437 $ 31 2020 33,859 176 2021 31,033 156 2022 27,272 150 2023 22,666 41 Thereafter 16,759 — Total future minimum lease payments 138,026 554 Less imputed interest (10,877 ) (79 ) Total $ 127,149 $ 475

Acquisitions (Tables)

Acquisitions (Tables)	9 Months Ended
	Sep. 30, 2019
H2M Group [Member]
Business Acquisition [Line Items]
Schedule of Business Acquisitions, by Acquisition [Table Text Block]	The following table represents the preliminary purchase price allocation for H2M (in thousands): Cash and cash equivalents $ 15 Receivables 4,011 Prepaid expenses 199 Other current assets 2 Goodwill 25,382 Other intangible assets 11,900 Operating lease ROU asset 145 Property and equipment 57 Other assets 7 Accounts payable and accrued expenses (1,775 ) Accrued salaries and related expenses (1,000 ) Operating lease liabilities - current (86 ) Operating lease liabilities - non current (60 ) Net assets acquired and liabilities assumed $ 38,797
Kforce Government Solutions [Member]
Business Acquisition [Line Items]
Schedule of Business Acquisitions, by Acquisition [Table Text Block]	The following table represents the preliminary purchase price allocation for KGS (in thousands): Cash and cash equivalents $ 154 Receivables 17,835 Prepaid expenses 368 Other current assets 168 Goodwill 80,025 Other intangible assets 34,839 Property and equipment 361 Accounts payable and accrued expenses (6,887 ) Accrued salaries and related expenses (4,421 ) Deferred income taxes (7,319 ) Other long-term liabilities (571 ) Net assets acquired and liabilities assumed $ 114,552

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]	The net income available to common stockholders and weighted average number of common shares outstanding used to compute basic and diluted earnings per share for each class of common stock are as follows (in thousands, except per share amounts): Three months ended Nine months ended 2019 2018 2019 2018 Distributed earnings $ 10,823 $ 9,928 $ 32,360 $ 29,687 Undistributed earnings 17,114 11,995 40,909 32,218 Net income $ 27,937 $ 21,923 $ 73,269 $ 61,905 Class A common stock: Basic net income available to common stockholders $ 18,729 $ 14,623 $ 49,048 $ 41,226 Basic weighted average common shares outstanding 26,822 26,421 26,706 26,293 Basic earnings per share $ 0.70 $ 0.55 $ 1.84 $ 1.57 Diluted net income available to common stockholders $ 18,798 $ 14,682 $ 49,203 $ 41,402 Effect of potential exercise of stock options 306 322 257 340 Diluted weighted average common shares outstanding 27,128 26,743 26,963 26,633 Diluted earnings per share $ 0.69 $ 0.55 $ 1.82 $ 1.55 Class B common stock: Basic net income available to common stockholders $ 9,208 $ 7,300 $ 24,221 $ 20,679 Basic weighted average common shares outstanding 13,188 13,189 13,188 13,189 Basic earnings per share $ 0.70 $ 0.55 $ 1.84 $ 1.57 Diluted net income available to common stockholders $ 9,139 $ 7,241 $ 24,066 $ 20,503 Diluted weighted average common shares outstanding 13,188 13,189 13,188 13,189 Diluted earnings per share $ 0.69 $ 0.55 $ 1.82 $ 1.55

Property and Equipment (Tables)

Property and Equipment (Tables)	9 Months Ended
	Sep. 30, 2019
Property, Plant and Equipment [Abstract]
Property and Equipment [Table Text Block]	Major classes of property and equipment are summarized as follows (in thousands): September 30, December 31, Furniture and equipment $ 131,114 $ 97,577 Leasehold improvements 48,421 43,065 Finance leases 669 — Property and equipment—gross 180,204 140,642 Accumulated depreciation and amortization (107,211 ) (89,215 ) Property and equipment—net $ 72,993 $ 51,427

Goodwill and Other Intangible_2

Goodwill and Other Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill [Table Text Block]	The change in the carrying amount of goodwill during the year ended December 31, 2018 and nine months ended September 30, 2019 are as follows (in thousands): Goodwill Balance Goodwill at December 31, 2017 $ 1,084,560 Acquisition fair value adjustment 1,246 Goodwill at December 31, 2018 1,085,806 Acquisitions 105,407 Goodwill at September 30, 2019 $ 1,191,213
Schedule of Other Intangible Assets [Table Text Block]	Other intangible assets consisted of the following (in thousands): September 30, 2019 December 31, 2018 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Other intangible assets: Contract and program intangible assets $ 402,532 $ 215,942 $ 186,590 $ 355,932 $ 201,298 $ 154,634 Capitalized software cost for internal use 53,322 36,665 16,657 50,925 33,597 17,328 Total other intangible assets—net $ 455,854 $ 252,607 $ 203,247 $ 406,857 $ 234,895 $ 171,962
Schedule of Other Intangible Assets, Future Amortization Expense [Table Text Block]	We estimate that we will have the following amortization expense for the future periods indicated below (in thousands): For the remaining three months ending December 31, 2019 $ 6,710 For the year ending: December 31, 2020 $ 25,301 December 31, 2021 $ 23,072 December 31, 2022 $ 20,139 December 31, 2023 $ 16,858 December 31, 2024 $ 15,151

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]	The following table summarizes weighted-average assumptions used in our calculations of fair value for the nine months ended September 30, 2019 and 2018 : Nine months ended 2019 2018 Volatility 27.00 % 26.34 % Expected life of options 3 years 3 years Risk-free interest rate 2.38 % 2.46 % Dividend yield 2.00 % 2.00 %
Share-based Payment Arrangement, Option, Activity [Table Text Block]	The following table summarizes stock option activity for the year ended December 31, 2018 and the nine months ended September 30, 2019 : Number of Shares Weighted Average Exercise Price Aggregate Intrinsic Value Weighted Average Remaining Contractual Life Stock options outstanding at December 31, 2017 1,169,408 $ 35.88 $ 16,731 Granted 466,828 $ 54.87 Exercised (420,524 ) $ 30.05 $ 12,411 Cancelled and expired (122,312 ) $ 43.85 Stock options outstanding at December 31, 2018 1,093,400 $ 45.34 $ 8,776 Granted 256,006 $ 53.81 Exercised (255,376 ) $ 35.82 $ 7,038 Cancelled and expired (97,005 ) $ 50.89 Stock options outstanding at September 30, 2019 997,025 $ 49.42 $ 21,927 3 years Stock options exercisable at September 30, 2019 221,597 $ 41.09 $ 6,719 2 years
Schedule of Non-vested Share Activity [Table Text Block]	The following table summarizes non-vested stock options for the nine months ended September 30, 2019 : Number of Shares Weighted Average Fair Value Non-vested stock options at December 31, 2018 774,402 $ 8.77 Granted 256,006 $ 10.10 Vested (161,114 ) $ 7.38 Cancelled (93,866 ) $ 9.23 Non-vested stock options at September 30, 2019 775,428 $ 9.44
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Share-based Compensation, Restricted Stock Activity [Table Text Block]	The following table summarizes the restricted stock activity during the year ended December 31, 2018 and the nine months ended September 30, 2019 . Number of Shares Weighted Average Fair Value Non-vested restricted stock at December 31, 2017 24,000 $ 37.90 Granted 24,000 $ 52.83 Vested (28,000 ) $ 40.03 Non-vested restricted stock at December 31, 2018 20,000 $ 52.83 Granted 24,000 $ 62.66 Vested (20,000 ) $ 52.83 Non-vested restricted stock at September 30, 2019 24,000 $ 62.66
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Share-based Compensation, Restricted Stock Activity [Table Text Block]	The following table summarizes the non-vested RSU activity during the year ended December 31, 2018 and the nine months ended September 30, 2019 : Number of Units Weighted Average Fair Value Non-vested RSUs at December 31, 2017 161,343 $ 31.36 Granted 76,713 $ 53.97 Vested (87,200 ) $ 28.40 Forfeited (13,260 ) $ 38.98 Non-vested RSUs at December 31, 2018 137,596 $ 45.11 Granted 99,675 $ 53.27 Vested (59,452 ) $ 42.46 Forfeited (10,677 ) $ 51.88 Non-vested RSUs at September 30, 2019 167,142 $ 50.48

Revenue from Contracts with C_3

Revenue from Contracts with Customers Narrative (Details) $ in Millions	Jan. 02, 2018USD ($)	Sep. 30, 2019USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2019USD ($)Entities	Sep. 30, 2018USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Contract with Customer, Asset, Cumulative Catch-up Adjustment to Revenue, Change in Measure of Progress		$ 5.9	$ 4.5	$ 9	$ 8.8
Number of Reportable Segments | Entities				1
Contract Receivable, Due after Next Rolling Twelve Months		$ 1.1		$ 1.1
Percentage of Accounts Receivable Not Expected to be Collected Within One Year related to Receivables from Direct Sales to U.S. Government		100.00%		100.00%
Revenue in Opening Contract Liabilities		$ 0.9		$ 23.4
Revenue, Remaining Performance Obligation, Amount		$ 3,100		$ 3,100
Accounting Standards Update 2014-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative Effect on Retained Earnings, before Tax	$ 0.8

Revenue from Contracts with C_4

Revenue from Contracts with Customers Revenue by Contract Type (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenue by Contract Type [Line Items]
Revenue	$ 579,179	$ 497,205	$ 1,618,146	$ 1,461,485
Cost reimbursable [Member]
Revenue by Contract Type [Line Items]
Revenue	397,921	337,105	1,129,538	970,647
Fixed-price Contract [Member]
Revenue by Contract Type [Line Items]
Revenue	120,632	108,921	323,723	341,854
Time-and-materials Contract [Member]
Revenue by Contract Type [Line Items]
Revenue	$ 60,626	$ 51,179	$ 164,885	$ 148,984

Revenue from Contracts with C_5

Revenue from Contracts with Customers Revenue by Customer (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenue from External Customer [Line Items]
Revenue	$ 579,179	$ 497,205	$ 1,618,146	$ 1,461,485
Department of Defense and intelligence agencies
Revenue from External Customer [Line Items]
Revenue	443,253	365,044	1,241,609	1,055,911
Federal civilian agencies
Revenue from External Customer [Line Items]
Revenue	124,243	121,543	341,880	371,767
State agencies, international agencies and commercial entities
Revenue from External Customer [Line Items]
Revenue	$ 11,683	$ 10,618	$ 34,657	$ 33,807

Revenue from Contracts with C_6

Revenue from Contracts with Customers Revenue by Contractor Type (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenue by Contractor Type [Line Items]
Revenue	$ 579,179	$ 497,205	$ 1,618,146	$ 1,461,485
Prime contractor
Revenue by Contractor Type [Line Items]
Revenue	524,370	442,413	1,448,875	1,298,437
Subcontractor
Revenue by Contractor Type [Line Items]
Revenue	$ 54,809	$ 54,792	$ 169,271	$ 163,048

Revenue from Contracts with C_7

Revenue from Contracts with Customers Revenue by Geographic Location (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 579,179	$ 497,205	$ 1,618,146	$ 1,461,485
U.S.
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	571,923	490,098	1,596,365	1,439,293
International
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 7,257	$ 7,107	$ 21,781	$ 22,192

Revenue from Contracts with C_8

Revenue from Contracts with Customers Schedule of Contract Receivables (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Billed receivables	$ 292,323	$ 301,716
Unbilled receivables	82,054	109,895
Allowance for doubtful accounts	(7,335)	(6,233)
Receivables—net	$ 367,042	$ 405,378

Revenue from Contracts with C_9

Revenue from Contracts with Customers Contract with Customer, Asset and Liability (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Contract liabilities	$ 43,891	$ 28,209

Revenue from Contracts with _10

Revenue from Contracts with Customers Revenue, Remaining Performance Obligation (Details) $ in Billions	Sep. 30, 2019USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 3.1
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	3 months
Revenue, Remaining Performance Obligation, Amount	$ 0.6
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Amount	$ 1.5
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Amount	$ 0.5
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period
Revenue, Remaining Performance Obligation, Amount	$ 0.5

Leases (Narrative) (Details)

Leases (Narrative) (Details) - USD ($)	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
Operating lease liability	$ 127,149,000	$ 127,149,000	$ 129,600,000
Operating lease right of use assets	116,236,000	116,236,000	$ 118,700,000	$ 0
Short-term Lease, Cost	1,400,000	4,200,000
Variable Lease, Cost	$ 500,000	$ 1,900,000
Minimum [Member]
Lessee Operating And Finance Leases Remaining Lease Term		1 day
Lessee Operating And Finance Lease, Option to Extend		1 year
Maximum [Member]
Lessee Operating And Finance Leases Remaining Lease Term		11 years
Lessee Operating And Finance Lease, Option to Extend		14 years

Leases Balance Sheet Informatio

Leases Balance Sheet Information (Details) - USD ($)	Sep. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
Operating Leases [Abstract]
Operating lease right of use assets	$ 116,236,000	$ 118,700,000	$ 0
Operating lease liabilities—current	28,170,000		0
Operating lease liabilities—long term	98,979,000		0
Total operating lease liabilities	127,149,000	$ 129,600,000
Finance Leases [Abstract]
Property and equipment—gross	669,000		$ 0
Accumulated depreciation	(194,000)
Property and equipment—net	475,000
Accounts payable and other accrued expenses	143,000
Other long-term liabilities	332,000
Total finance lease liabilities	$ 475,000

Leases Cost (Details)

Leases Cost (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Leases [Abstract]
Operating lease expenses	$ 8,412	$ 24,727
Finance Leases [Abstract]
Depreciation of right of use assets	45	194
Interest on lease liabilities	19	33
Finance lease expenses	$ 64	$ 227

Leases Term and Discount Rate (

Leases Term and Discount Rate (Details)	Sep. 30, 2019
Weighted Average Remaining Lease Term [Abstract]
Operating Lease, Weighted Average Remaining Lease Term	5 years
Finance Lease, Weighted Average Remaining Lease Term	3 years
Weighted Average Discount Rate [Abstract]
Operating Lease, Weighted Average Discount Rate, Percent	3.00%
Finance Lease, Weighted Average Discount Rate, Percent	5.00%

Leases Schedule of Maturity of

Leases Schedule of Maturity of Lease Liabilities (Details) - USD ($)	Sep. 30, 2019	Jan. 01, 2019
Operating Lease Liabilities, Payments, Due [Abstract]
For the three months ended December 31, 2019	$ 6,437,000
2020	33,859,000
2021	31,033,000
2022	27,272,000
2023	22,666,000
Thereafter	16,759,000
Total future minimum lease payments	138,026,000
Less imputed interest	(10,877,000)
Total	127,149,000	$ 129,600,000
Finance Lease, Liability, Payment, Due [Abstract]
For the three months ended December 31, 2019	31,000
2020	176,000
2021	156,000
2022	150,000
2023	41,000
Thereafter	0
Total future minimum lease payments	554,000
Less imputed interest	(79,000)
Total	$ 475,000

Acquisitions Narrative (Details

Acquisitions Narrative (Details) $ in Millions	9 Months Ended
	Sep. 30, 2019USD ($)
H2M Group [Member]
Business Combination, Separately Recognized Transactions, Additional Disclosures, Acquisition Cost Expensed	$ 0.3
Business Combination, Consideration Transferred	$ 38.8
Expected Goodwill Tax Amortization Period	15 years
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	17 years
Kforce Government Solutions [Member]
Business Combination, Separately Recognized Transactions, Additional Disclosures, Acquisition Cost Expensed	$ 1
Business Combination, Consideration Transferred	$ 114.6
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	19 years
Customer Relationships [Member] | H2M Group [Member]
Finite-lived Intangible Assets Acquired	$ 9.6
Finite-Lived Intangible Asset, Useful Life	20 years
Customer Relationships [Member] | Kforce Government Solutions [Member]
Finite-lived Intangible Assets Acquired	$ 33.1
Finite-Lived Intangible Asset, Useful Life	20 years
Backlog [Member] | H2M Group [Member]
Finite-lived Intangible Assets Acquired	$ 2.3
Finite-Lived Intangible Asset, Useful Life	2 years
Backlog [Member] | Kforce Government Solutions [Member]
Finite-lived Intangible Assets Acquired	$ 1.6
Finite-Lived Intangible Asset, Useful Life	1 year

Acquisitions Schedule of Purcha

Acquisitions Schedule of Purchase Price Allocation (Details) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Goodwill	$ 1,191,213	$ 1,085,806	$ 1,084,560
H2M Group [Member]
Business Acquisition [Line Items]
Cash and cash equivalents	15
Receivables	4,011
Prepaid expenses	199
Other current assets	2
Goodwill	25,382
Other intangible assets	11,900
Operating lease ROU asset	145
Property and equipment	57
Other assets	7
Accounts payable and accrued expenses	(1,775)
Accrued salaries and related expenses	(1,000)
Operating lease liabilities - current	(86)
Operating lease liabilities - non current	(60)
Net assets acquired and liabilities assumed	38,797
Kforce Government Solutions [Member]
Business Acquisition [Line Items]
Cash and cash equivalents	154
Receivables	17,835
Prepaid expenses	368
Other current assets	168
Goodwill	80,025
Other intangible assets	34,839
Property and equipment	361
Accounts payable and accrued expenses	(6,887)
Accrued salaries and related expenses	(4,421)
Deferred income taxes	(7,319)
Other long-term liabilities	(571)
Net assets acquired and liabilities assumed	$ 114,552

Earnings Per Share (Narrative)

Earnings Per Share (Narrative) (Details) - $ / shares	3 Months Ended						9 Months Ended		12 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Earnings Per Share [Abstract]
Common Stock, Dividends, Per Share, Cash Paid	$ 0.27	$ 0.27	$ 0.27	$ 0.25	$ 0.25	$ 0.25
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	7,641			242,789			331,994	268,013
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period							255,376	387,926	420,524
Stock Issued During Period, Shares, Restricted Stock Vesting							76,346	86,233

Earnings Per Share (Schedule of

Earnings Per Share (Schedule of Earnings Per Share, Basic and Diluted) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Components of Earnings Per Share, Basic and Diluted [Line Items]
Distributed earnings	$ 10,823	$ 9,928	$ 32,360	$ 29,687
Undistributed earnings	17,114	11,995	40,909	32,218
Net income	27,937	21,923	73,269	61,905
Class A common stock
Components of Earnings Per Share, Basic and Diluted [Line Items]
Basic net income available to common stockholders	$ 18,729	$ 14,623	$ 49,048	$ 41,226
Basic weighted average common shares outstanding	26,822	26,421	26,706	26,293
Basic earnings per share	$ 0.70	$ 0.55	$ 1.84	$ 1.57
Diluted net income available to common stockholders	$ 18,798	$ 14,682	$ 49,203	$ 41,402
Effect of potential exercise of stock options	306	322	257	340
Diluted weighted average common shares outstanding	27,128	26,743	26,963	26,633
Diluted earnings per share	$ 0.69	$ 0.55	$ 1.82	$ 1.55
Class B common stock
Components of Earnings Per Share, Basic and Diluted [Line Items]
Basic net income available to common stockholders	$ 9,208	$ 7,300	$ 24,221	$ 20,679
Basic weighted average common shares outstanding	13,188	13,189	13,188	13,189
Basic earnings per share	$ 0.70	$ 0.55	$ 1.84	$ 1.57
Diluted net income available to common stockholders	$ 9,139	$ 7,241	$ 24,066	$ 20,503
Diluted weighted average common shares outstanding	13,188	13,189	13,188	13,189
Diluted earnings per share	$ 0.69	$ 0.55	$ 1.82	$ 1.55

Property and Equipment (Propert

Property and Equipment (Property and Equipment) (Details) - USD ($)	Sep. 30, 2019	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Furniture and equipment	$ 131,114,000	$ 97,577,000
Leasehold improvements	48,421,000	43,065,000
Finance leases	669,000	0
Property and equipment—gross	180,204,000	140,642,000
Accumulated depreciation and amortization	(107,211,000)	(89,215,000)
Property and equipment—net	$ 72,993,000	$ 51,427,000

Property and Equipment Narrativ

Property and Equipment Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Property, Plant and Equipment [Abstract]
Depreciation and amortization expense related to property and equipment	$ 6.9	$ 6.4	$ 19.4	$ 19.1

Goodwill and Other Intangible_3

Goodwill and Other Intangible Assets (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization of Intangible Assets	$ 6.1	$ 6.8	$ 18	$ 20.3

Goodwill and Other Intangible_4

Goodwill and Other Intangible Assets (Schedule of Goodwill) (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Goodwill [Roll Forward]
Goodwill	$ 1,085,806	$ 1,084,560
Acquisition fair value adjustment		1,246
Acquisitions	105,407
Goodwill	$ 1,191,213	$ 1,085,806

Goodwill and Other Intangible_5

Goodwill and Other Intangible Assets (Schedule of Other Intangible Assets) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 455,854	$ 406,857
Accumulated Amortization	252,607	234,895
Net Carrying Amount	203,247	171,962
Contract and program intangible assets
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	402,532	355,932
Accumulated Amortization	215,942	201,298
Net Carrying Amount	186,590	154,634
Capitalized software cost for internal use
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	53,322	50,925
Accumulated Amortization	36,665	33,597
Net Carrying Amount	$ 16,657	$ 17,328

Goodwill and Other Intangible_6

Goodwill and Other Intangible Assets (Schedule of Other Intangible Assets, Future Amortization Expense) (Details) $ in Thousands	Sep. 30, 2019USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
For the remaining three months ending December 31, 2019	$ 6,710
For the year ending:
December 31, 2020	25,301
December 31, 2021	23,072
December 31, 2022	20,139
December 31, 2023	16,858
December 31, 2024	$ 15,151

Debt (Revolving Credit Facility

Debt (Revolving Credit Facility) (Narrative) (Details) - USD ($)	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Line of Credit Facility [Line Items]
Long-term Line of Credit	$ 25,000,000	$ 7,500,000
Bank of America Syndicate [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	500,000,000
Long-term Line of Credit	25,000,000	$ 7,500,000
Line of Credit Facility, Remaining Borrowing Capacity	467,300,000
Bank of America Syndicate [Member] | Letter of Credit [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	75,000,000
Contingent Liability under Letters of Credit	7,700,000
Bank of America Syndicate [Member] | Revolving Credit Facility, Swing Line Loan [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 30,000,000
London Interbank Offered Rate (LIBOR) [Member] | Revolving Credit Facility [Member] | Minimum [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.25%
London Interbank Offered Rate (LIBOR) [Member] | Revolving Credit Facility [Member] | Maximum [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	2.25%
Bank of America's Base Rate [Member] | Revolving Credit Facility [Member] | Minimum [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.25%
Bank of America's Base Rate [Member] | Revolving Credit Facility [Member] | Maximum [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.25%

Commitments and Contingencies_2

Commitments and Contingencies (Letter of Credit) (Narrative) (Details) - Letter of Credit [Member] - Bank of America Syndicate [Member] $ in Millions	Sep. 30, 2019USD ($)
Line of Credit Facility [Line Items]
Letters of Credit Outstanding, Amount	$ 7.7
Performance Guarantee [Member]
Line of Credit Facility [Line Items]
Letters of Credit Outstanding, Amount	$ 7.6

Stock-Based Compensation (Narra

Stock-Based Compensation (Narrative) (Details) - USD ($)	Jan. 02, 2019	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual Percentage Increase In Number Of Shares Available For Issuance	1.50%
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized	596,422
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized		15,148,321		15,148,321
Remaining Aggregate Number of Shares Available For Issuance		6,727,002		6,727,002
Share-based Compensation		$ 2,000,000	$ 1,300,000	$ 5,200,000	$ 3,600,000
Share-based Payment Arrangement, Amount Capitalized				0	0
Income tax expense (benefit) related to the exercise of stock options, vested cancellations and the vesting of restricted stock and restricted stock units		(900,000)	$ (1,200,000)	$ (1,600,000)	$ (2,900,000)
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period				3 years	3 years
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period				5 years	5 years
Expected Annual Cash Dividend				$ 1.08
Granted, Weighted Average Fair Value				$ 10.10	$ 9.98
Share-based Payment Award, Options, Vested, Fair Value				$ 1,200,000	$ 700,000
Share-based Compensation, Nonvested Awards, Total Compensation Cost Not Yet Recognized		$ 5,100,000		$ 5,100,000
Share-based Compensation, Nonvested Awards, Total Compensation Cost Not Yet Recognized, Period for Recognition				2 years
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period				8 years	8 years
Restricted Stock [Member] | Director [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period				1 year	1 year
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RSU Performance Factor, Number of Shares Issued				1.5	1.5

Stock-Based Compensation (Sched

Stock-Based Compensation (Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions) (Details)	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Share-based Payment Arrangement, Noncash Expense [Abstract]
Volatility	27.00%	26.34%
Expected life of options	3 years	3 years
Risk-free interest rate	2.38%	2.46%
Dividend yield	2.00%	2.00%

Stock-Based Compensation (Sch_2

Stock-Based Compensation (Schedule of Share-based Compensation, Stock Options, Activity) (Details) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018	Dec. 31, 2017
Share-based Payment Award, Options, Outstanding [Roll Forward]
Stock options, Number of Shares, Period Start	1,093,400	1,169,408	1,169,408
Granted, Number of Shares	256,006		466,828
Exercised, Number of Shares	(255,376)	(387,926)	(420,524)
Cancelled and expired, Number of Shares	(97,005)		(122,312)
Stock options, Number of Shares, Period End	997,025		1,093,400
Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Stock options, Weighted Average Exercise Price, Period Start	$ 45.34	$ 35.88	$ 35.88
Granted, Weighted Average Exercise Price	53.81		54.87
Exercised, Weighted Average Exercise Price	35.82		30.05
Cancelled and expired, Weighted Average Exercise Price	50.89		43.85
Stock options, Weighted Average Exercise Price, Period End	$ 49.42		$ 45.34
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Stock options outstanding, Aggregate Intrinsic Value	$ 21,927		$ 8,776	$ 16,731
Exercised, Aggregate Intrinsic Value	$ 7,038		$ 12,411
Stock options outstanding, Weighted Average Remaining Contractual Life	3 years
Stock options exercisable, Number of Shares	221,597
Stock options exercisable, Weighted Average Exercise Price	$ 41.09
Stock options exercisable, Aggregate Intrinsic Value	$ 6,719
Stock options exercisable, Weighted Average Remaining Contractual Life	2 years

Stock-Based Compensation (Sch_3

Stock-Based Compensation (Schedule of Non-vested Share Activity) (Details) - $ / shares	9 Months Ended		12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award, Options, Non-vested [Roll Forward]
Non-vested stock options, Number of Shares, Period Start	774,402
Granted, Number of Shares	256,006		466,828
Vested, Number of Shares	(161,114)
Cancelled, Number of Shares	(93,866)
Non-vested stock options, Number of Shares, Period End	775,428		774,402
Share-based Compensation Arrangement by Share-based Payment Award, Options, Non-vested, Weighted Average Grant Date Fair Value [Roll Forward]
Non-vested stock options, Weighted Average Fair Value, Period Start	$ 8.77
Granted, Weighted Average Fair Value	10.10	$ 9.98
Vested, Weighted Average Fair Value	7.38
Cancelled, Weighted Average Fair Value	9.23
Non-vested stock options, Weighted Average Fair Value, Period End	$ 9.44		$ 8.77

Stock-Based Compensation (Sch_4

Stock-Based Compensation (Schedule Of Share-based Compensation, Restricted Stock Activity) (Details) - Restricted Stock [Member] - $ / shares	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award, Restricted Stock, Non-vested [Roll Forward]
Non-vested, Period Start	20,000	24,000
Granted	24,000	24,000
Vested	(20,000)	(28,000)
Non-vested, Period End	24,000	20,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Non-vested, Weighted Average Fair Value, Period Start	$ 52.83	$ 37.90
Granted, Weighted Average Fair Value	62.66	52.83
Vested, Weighted Average Fair Value	52.83	40.03
Non-vested, Weighted Average Fair Value, Period End	$ 62.66	$ 52.83

Stock-Based Compensation (Sch_5

Stock-Based Compensation (Schedule of Share-based Compensation, Restricted Stock Unit Activity) (Details) - Restricted Stock Units (RSUs) [Member] - $ / shares	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award, Restricted Stock Units, Nonvested, Number of Shares [Roll Forward]
Non-vested, Period Start	137,596	161,343
Granted	99,675	76,713
Vested	(59,452)	(87,200)
Forfeited	(10,677)	(13,260)
Non-vested, Period End	167,142	137,596
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Non-vested, Weighted Average Fair Value, Period Start	$ 45.11	$ 31.36
Granted, Weighted Average Fair Value	53.27	53.97
Vested, Weighted Average Fair Value	42.46	28.40
Forfeited, Weighted Average Fair Value	51.88	38.98
Non-vested, Weighted Average Fair Value, Period End	$ 50.48	$ 45.11