Mantech International (MANT) 10-Q 3 Nov 21 2021 Q3 Quarterly report Financial data

Cover Page Cover Page

Cover Page Cover Page - shares	9 Months Ended
	Sep. 30, 2021	Nov. 01, 2021
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2021
Document Transition Report	false
Entity File Number	000-49604
Entity Registrant Name	ManTech International Corporation
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	2021
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		27,562,407
Class B common stock
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		13,176,695

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($)	Sep. 30, 2021	Dec. 31, 2020
ASSETS
Cash and cash equivalents	$ 145,414,000	$ 41,193,000
Receivables—net	389,403,000	400,621,000
Prepaid expenses	30,752,000	26,243,000
Taxes receivable—current	17,838,000	21,968,000
Other current assets	8,339,000	6,354,000
Total Current Assets	591,746,000	496,379,000
Goodwill	1,238,090,000	1,237,894,000
Other intangible assets—net	182,234,000	202,231,000
Property and equipment—net	127,042,000	121,296,000
Operating lease right of use assets	79,266,000	94,825,000
Employee supplemental savings plan assets	40,996,000	37,848,000
Investments	11,555,000	11,549,000
Other assets	13,232,000	11,642,000
TOTAL ASSETS	2,284,161,000	2,213,664,000
LIABILITIES
Accounts payable	164,387,000	142,360,000
Accrued salaries and related expenses	121,767,000	123,953,000
Contract liabilities	34,442,000	37,218,000
Operating lease obligations—current	31,291,000	30,105,000
Accrued expenses and other current liabilities	8,924,000	15,177,000
Total Current Liabilities	360,811,000	348,813,000
Deferred income taxes	152,586,000	141,638,000
Operating lease obligations—long term	67,306,000	80,242,000
Accrued retirement	34,841,000	36,310,000
Long-term debt	0	15,000,000
Other long-term liabilities	12,215,000	12,249,000
TOTAL LIABILITIES	627,759,000	634,252,000
COMMITMENTS AND CONTINGENCIES
STOCKHOLDERS' EQUITY
Additional paid-in capital	562,159,000	545,717,000
Treasury stock	(9,158,000)	(9,158,000)
Retained earnings	1,103,243,000	1,042,676,000
Accumulated other comprehensive loss	(252,000)	(230,000)
TOTAL STOCKHOLDERS' EQUITY	1,656,402,000	1,579,412,000
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	2,284,161,000	2,213,664,000
Class A common stock
STOCKHOLDERS' EQUITY
Common stock	278,000	275,000
Class B common stock
STOCKHOLDERS' EQUITY
Common stock	$ 132,000	$ 132,000

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets Parentheticals - $ / shares	Sep. 30, 2021	Dec. 31, 2020
Treasury Stock, Shares	244,113	244,113
Class A common stock
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Common Stock, Shares Authorized	150,000,000	150,000,000
Common Stock, Shares, Issued	27,803,379	27,538,474
Common Stock, Shares, Outstanding	27,559,266	27,294,361
Class B common stock
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Common Stock, Shares Authorized	50,000,000	50,000,000
Common Stock, Shares, Issued	13,176,695	13,176,695
Common Stock, Shares, Outstanding	13,176,695	13,176,695

Condensed Consolidated Statemen

Condensed Consolidated Statements of Income - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
REVENUE	$ 637,821,000	$ 636,196,000	$ 1,919,623,000	$ 1,879,600,000
Cost of services	536,205,000	538,000,000	1,631,790,000	1,597,764,000
General and administrative expenses	48,343,000	58,855,000	143,477,000	164,011,000
OPERATING INCOME	53,273,000	39,341,000	144,356,000	117,825,000
Interest expense	(606,000)	(310,000)	(1,326,000)	(1,597,000)
Interest income	36,000	40,000	115,000	227,000
Other (expense), net	(92,000)	(29,000)	(225,000)	(51,000)
INCOME FROM OPERATIONS BEFORE INCOME TAXES AND EQUITY METHOD INVESTMENTS	52,611,000	39,042,000	142,920,000	116,404,000
Provision for income taxes	(14,655,000)	(9,303,000)	(36,026,000)	(28,037,000)
Equity in losses of unconsolidated subsidiaries	0	0	(1,000)	(1,000)
NET INCOME	$ 37,956,000	$ 29,739,000	$ 106,893,000	$ 88,366,000
Class A common stock
BASIC EARNINGS PER SHARE:
Basic earnings per share	$ 0.93	$ 0.74	$ 2.63	$ 2.19
DILUTED EARNINGS PER SHARE:
Diluted earnings per share	0.93	0.73	2.61	2.18
Class B common stock
BASIC EARNINGS PER SHARE:
Basic earnings per share	0.93	0.74	2.63	2.19
DILUTED EARNINGS PER SHARE:
Diluted earnings per share	$ 0.93	$ 0.73	$ 2.61	$ 2.18

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
NET INCOME	$ 37,956	$ 29,739	$ 106,893	$ 88,366
OTHER COMPREHENSIVE LOSS:
Translation adjustments, net of tax	(3)	(19)	(22)	(44)
Total other comprehensive loss	(3)	(19)	(22)	(44)
COMPREHENSIVE INCOME	$ 37,953	$ 29,720	$ 106,871	$ 88,322

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Changes in Stockholders' Equity Statement - USD ($)	Total	Common StockCommon Stock, Class A	Common StockCommon Stock, Class B	Additional Paid-In Capital	Treasury Stock, at cost	Retained Earnings	Accumulated Other Comprehensive Loss
At beginning of period at Dec. 31, 2019		$ 272,000	$ 132,000	$ 525,851,000	$ (9,158,000)	$ 973,767,000	$ (222,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock option exercises		1,000		5,917,000
Stock-based compensation expense	$ 8,533,000	1,000		8,532,000
Payment consideration to tax authority on employees' behalf				(1,014,000)
Net income	88,366,000					88,366,000
Dividends						(38,685,000)
Translation adjustments, net of tax	(44,000)						(44,000)
At end of period at Sep. 30, 2020	1,553,716,000	274,000	132,000	539,286,000	(9,158,000)	1,023,448,000	(266,000)
At beginning of period at Jun. 30, 2020		274,000	132,000	535,464,000	(9,158,000)	1,006,624,000	(247,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock option exercises		0		1,036,000
Stock-based compensation expense		0		3,023,000
Payment consideration to tax authority on employees' behalf				(237,000)
Net income	29,739,000					29,739,000
Dividends						(12,915,000)
Translation adjustments, net of tax	(19,000)						(19,000)
At end of period at Sep. 30, 2020	1,553,716,000	274,000	132,000	539,286,000	(9,158,000)	1,023,448,000	(266,000)
At beginning of period at Dec. 31, 2020	1,579,412,000	275,000	132,000	545,717,000	(9,158,000)	1,042,676,000	(230,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock option exercises		2,000		8,019,000
Stock-based compensation expense	11,516,000	1,000		11,515,000
Payment consideration to tax authority on employees' behalf				(3,092,000)
Net income	106,893,000					106,893,000
Dividends						(46,326,000)
Translation adjustments, net of tax	(22,000)						(22,000)
At end of period at Sep. 30, 2021	1,656,402,000	278,000	132,000	562,159,000	(9,158,000)	1,103,243,000	(252,000)
At beginning of period at Jun. 30, 2021		278,000	132,000	557,211,000	(9,158,000)	1,080,762,000	(249,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock option exercises		0		1,587,000
Stock-based compensation expense		0		3,960,000
Payment consideration to tax authority on employees' behalf				(599,000)
Net income	37,956,000					37,956,000
Dividends						(15,475,000)
Translation adjustments, net of tax	(3,000)						(3,000)
At end of period at Sep. 30, 2021	$ 1,656,402,000	$ 278,000	$ 132,000	$ 562,159,000	$ (9,158,000)	$ 1,103,243,000	$ (252,000)

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows - USD ($)	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
CASH FLOWS FROM (USED IN) OPERATING ACTIVITIES:
Net income	$ 106,893,000	$ 88,366,000
Adjustments to reconcile net income to net cash flow from (used in) operating activities:
Depreciation and amortization	57,438,000	51,281,000
Noncash lease expense	27,002,000	20,738,000
Stock-based compensation expense	11,516,000	8,533,000
Deferred income taxes	10,948,000	11,127,000
Change in allowance for bad debts	(3,499,000)	5,244,000
Contract loss reserve	0	(372,000)
Change in assets and liabilities—net of effects from acquired businesses:
Receivables—net	14,638,000	10,877,000
Taxes receivable—current	4,130,000	(5,825,000)
Prepaid expenses	(3,843,000)	(7,838,000)
Other current assets	1,180,000	(1,333,000)
Employee supplemental savings plan asset	(3,375,000)	(2,042,000)
Other long-term assets	(3,775,000)	(1,939,000)
Accounts payable	24,850,000	23,490,000
Operating lease obligations	(26,465,000)	(22,102,000)
Accrued expenses and other current liabilities	(6,753,000)	(925,000)
Contract liabilities	(2,292,000)	12,438,000
Accrued salaries and related expenses	(2,123,000)	29,812,000
Accrued retirement	(1,469,000)	(2,328,000)
Other long-term liabilities	0	100,000
Other	49,000	(169,000)
Net cash flow from operating activities	205,050,000	217,133,000
CASH FLOWS FROM (USED IN) INVESTING ACTIVITIES:
Purchases of property and equipment	(41,199,000)	(53,685,000)
Proceeds from corporate owned life insurance	227,000	4,137,000
Investment in capitalized software	0	(5,193,000)
Proceeds from sale of property and equipment	0	869,000
Net cash (used in) investing activities	(40,972,000)	(53,872,000)
CASH FLOWS FROM (USED IN) FINANCING ACTIVITIES:
Borrowing under credit agreement	207,500,000	285,500,000
Repayments under credit agreement	(222,500,000)	(322,000,000)
Dividends paid	(46,332,000)	(38,689,000)
Proceeds from exercise of stock options	8,020,000	5,918,000
Debt issuance costs	(3,315,000)	0
Payment consideration to tax authority on employees' behalf	(3,092,000)	(1,014,000)
Principal paid on financing leases	(138,000)	(118,000)
Net cash (used in) financing activities	(59,857,000)	(70,403,000)
NET CHANGE IN CASH AND CASH EQUIVALENTS	104,221,000	92,858,000
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	41,193,000	8,854,000
CASH AND CASH EQUIVALENTS, END OF PERIOD	145,414,000	101,712,000
SUPPLEMENTAL CASH FLOW INFORMATION
Cash paid for interest	1,008,000	1,568,000
Cash paid for income taxes, net of refunds	20,789,000	22,619,000
Noncash investing and financing activities:
Operating lease obligations arising from obtaining right of use assets	14,685,000	6,459,000
Finance lease obligations arising from obtaining right of use assets	141,000	107,000
Noncash investing activities	$ (319,000)	$ 5,480,000

Description of the Business (No

Description of the Business (Notes)	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of the Business [Text Block]	Description of the BusinessManTech International Corporation (depending on the circumstances, “ManTech” “Company” “we” “our” “ours” or “us”) provides mission-focused technology solutions and services for U.S. defense, intelligence community and federal civilian agencies. We excel in full-spectrum cyber, data collection & analytics, enterprise information technology (IT) and systems engineering and software application development solutions that support national and homeland security.

Basis of Presentation (Notes)

Basis of Presentation (Notes)	9 Months Ended
	Sep. 30, 2021
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, 2020, 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. We classify indirect cost incurred as cost of services and general and administrative expenses in the same manner as such costs are defined in our disclosure statements under U.S. Government Cost Accounting Standards. Effective January 1, 2021, we updated our disclosure statements with the Defense Contract Management Agency, resulting in certain costs being classified differently either as cost of services or as general and administrative expenses on a prospective basis. This change has caused a net increase in the reported cost of services and a net decrease in reported general and administrative expenses in 2021 as compared to 2020; however, total operating costs were not affected by this change.

Revenue from Contracts with Cus

Revenue from Contracts with Customers (Notes)	9 Months Ended
	Sep. 30, 2021
Revenue from Contract with Customer [Abstract]
Revenue from Contracts with Customer [Text Block]	Revenue from Contracts with Customers 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. 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, 2021 and 2020, the aggregate impact of adjustments in contract estimates increased our revenue by $3.7 million and $4.3 million, respectively. For nine months ended September 30, 2021 and 2020, the aggregate impact of adjustments in contract estimates increased our revenue by $8.1 million and $9.4 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. We generated 100% and 99% of our revenue from sales in the U.S. for each of the three months ended September 30, 2021 and 2020, respectively. We generated 100% and 99% of our revenue from sales in the U.S. for each of the nine months ended September 30, 2021 and 2020, respectively. The following tables disclose revenue (in thousands) by contract type, customer and contractor type for the periods presented. Three months ended Nine months ended 2021 2020 2021 2020 Cost-reimbursable $ 441,588 $ 431,991 $ 1,305,313 $ 1,283,522 Fixed-price 113,122 126,402 362,804 368,316 Time-and-materials 83,111 77,803 251,506 227,762 Revenue $ 637,821 $ 636,196 $ 1,919,623 $ 1,879,600 Three months ended Nine months ended 2021 2020 2021 2020 U.S. Government $ 631,765 $ 624,888 $ 1,903,018 $ 1,848,043 State agencies, international agencies and commercial entities 6,056 11,308 16,605 31,557 Revenue $ 637,821 $ 636,196 $ 1,919,623 $ 1,879,600 Three months ended Nine months ended 2021 2020 2021 2020 Prime contractor $ 596,420 $ 579,858 $ 1,787,800 $ 1,712,403 Subcontractor 41,401 56,338 131,823 167,197 Revenue $ 637,821 $ 636,196 $ 1,919,623 $ 1,879,600 The components of our receivables are as follows (in thousands): September 30, 2021 December 31, 2020 Billed receivables $ 313,336 $ 312,991 Unbilled receivables 91,251 106,007 Allowance for doubtful accounts (15,184) (18,377) Receivables—net $ 389,403 $ 400,621 Receivables at September 30, 2021 are expected to be substantially collected within one year except for approximately $4.1 million, of which a majority is related to U.S. government receivables. 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. At September 30, 2021 and December 31, 2020, our contract liabilities are $34.4 million and $37.2 million, respectively. Changes in the balance of contract liabilities are primarily due to the timing difference between our performance and our customers' payments. For the three months ended September 30, 2021, the amount of revenue that was included in the opening contract liabilities balance was $1.2 million. For the nine months ended September 30, 2021, the amount of revenue that was included in the opening contract liabilities balance was $30.6 million. The remaining performance obligation as of September 30, 2021 is $2.2 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, 2021 For the year ending December 31, 2022 December 31, 2023 Thereafter $ 0.6 $ 1.0 $ 0.2 $ 0.4

Leases (Notes)

Leases (Notes)	9 Months Ended
	Sep. 30, 2021
Leases [Abstract]
Lessee, Operating Leases	Leases Our operating leases are primarily made up of real estate. Our finance leases are primarily made up of transportation vehicles and equipment. There have been no material changes to our finance leases from the Form 10-K filed as of December 31, 2020. The balance sheet information related to our operating leases was as follows (dollars in thousands): September 30, 2021 December 31, 2020 Operating Leases Operating lease right of use assets $ 79,266 $ 94,825 Operating lease obligations—current $ 31,291 $ 30,105 Operating lease obligations—long term $ 67,306 $ 80,242 The components of operating lease expense are as follows: Three months ended Nine months ended 2021 2020 2021 2020 Operating lease expense $ 12,004 $ 8,465 $ 28,907 $ 25,548

Acquisitions (Notes)

Acquisitions (Notes)	9 Months Ended
	Sep. 30, 2021
Business Combinations [Abstract]
Acquisitions	Acquisitions Tapestry Technologies (Tapestry) —On December 11, 2020, we completed the acquisition of Tapestry through a share purchase agreement by and among ManTech International Corporation, Tapestry Technologies, Inc., Project Tribune Holdings, Inc. (Holdco), and all of the shareholders of the Holdco. Tapestry provides unique insight and cybersecurity solutions to the U.S. Defense Information Systems Agency (DISA) and the Department of Defense (DoD). This acquisition broadens our footprint with DISA, serves as a springboard into the broader Defense Department IT marketspace, and provides us access to well-funded DISA and DoD programs. The acquisition was accounted for as a business combination. The results of Tapestry's operations have been included in our condensed consolidated financial statements since that date. We funded the acquisition with cash on hand and borrowing under our revolving credit facility. The purchase price of $46.3 million has been allocated to the underlying assets and liabilities based on their estimated fair value at the date of acquisition. The excess of the purchase price over the fair value of assets acquired and liabilities assumed was recorded as goodwill. The purchase price allocation for Tapestry is complete as of September 30, 2021. Recognition of goodwill is largely attributed to the value paid for Tapestry's capabilities, which will broaden our footprint within DISA and the Defense Department IT marketplace. The goodwill recorded for this transaction will be deductible for tax purposes over 15 years. The components of other intangible assets associated with the acquisition were customer relationships and backlog valued at $15.1 million and $1.4 million, respectively. The fair values of the customer relationships and backlog were determined using the excess earnings method (income approach) in which the value is derived from an estimation of the after-tax cash flows specifically attributable to backlog and customer relationships. Assumptions used in the analysis included revenue and expense forecasts, contributory asset charges, tax amortization benefit and discount rates. Customer contracts and related relationships represent the underlying relationships and agreements with Tapestry'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 of other intangibles is 18 years. The following table represents the purchase price allocation for Tapestry (in thousands): Cash and cash equivalents $ 36 Receivables 3,926 Prepaid expenses 225 Goodwill 27,013 Other intangible assets 16,500 Property and equipment 269 Operating lease right of use assets 934 Other assets 10 Accounts payable (522) Accrued salaries and related expenses (1,142) Operating lease obligations—current (487) Accrued expenses and other current liabilities (59) Operating lease obligations—long term (453) Net assets acquired and liabilities assumed $ 46,250 Minerva Engineering (Minerva) —On November 9, 2020, we completed the acquisition of Minerva through a membership interest purchase agreement by and among ManTech International Corporation, Minerva Engineering, LLC and NH Holdco LLC. Minerva is a leading provider of advanced cyber services that support the intelligence community, including risk and vulnerability assessment, incident response and cyber intrusion detection, and wireless signal discovery. This acquisition enhances and expands our cyber defense capabilities within the intelligence community, adding new customers, new past performance qualifications, mission-critical contracts, and highly skilled, cleared professionals that increase our deep cyber security talent base. The acquisition was accounted for as a business combination. The results of Minerva's operations have been included in our condensed consolidated financial statements since that date. We paid for the acquisition with cash on November 9, 2020 and a short-term promissory note that was paid on November 12, 2020. The preliminary purchase price, which includes a finalized working capital adjustment, was $32.7 million. The preliminary purchase price has been preliminarily allocated to the underlying assets and liabilities based on their estimated fair value at the date of acquisition. The excess of the purchase price over the fair value of assets acquired and liabilities assumed was recorded as goodwill. As we are still in the process of reviewing the fair value of the assets acquired and liabilities assumed, the purchase price allocation for Minerva is not complete as of September 30, 2021. In accordance with ASC 805, Business Combinations , we expect to finalize our purchase price allocation within one year of the acquisition date. Recognition of goodwill is largely attributed to the value paid for Minerva's capabilities, which will broaden our footprint within the intelligence community through the addition of differentiated capabilities and access to new customers and contracts. The goodwill recorded for this transaction will be deductible for tax purposes over 15 years. The components of other intangible assets associated with the acquisition were customer relationships and backlog valued at $10.5 million and $1.1 million, respectively. The fair values of the customer relationships and backlog were determined using the excess earnings method (income approach) in which the value is derived from an estimation of the after-tax cash flows specifically attributable to backlog and customer relationships. Assumptions used in the analysis included revenue and expense forecasts, contributory asset charges, tax amortization benefit and discount rates. Customer contracts and related relationships represent the underlying relationships and agreements with Minerva'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 other intangible assets is 18 years. The following table represents the preliminary purchase price allocation for Minerva (in thousands): Cash and cash equivalents $ 56 Receivables 4,181 Prepaid expenses 28 Goodwill 19,807 Other intangible assets 11,600 Property and equipment 149 Operating lease right of use assets 968 Other assets 29 Accounts payable (1,875) Accrued salaries and related expenses (784) Operating lease obligations—current (384) Accrued expenses and other current liabilities (555) Operating lease obligations—long term (562) Net assets acquired and liabilities assumed $ 32,658

Earnings Per Share (Notes)

Earnings Per Share (Notes)	9 Months Ended
	Sep. 30, 2021
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, 2021 and 2020, we declared and paid quarterly dividends in the amounts of $0.38 per share and $0.32 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 2021 2020 2021 2020 Distributed earnings $ 15,475 $ 12,915 $ 46,326 $ 38,685 Undistributed earnings 22,481 16,824 60,567 49,681 Net income $ 37,956 $ 29,739 $ 106,893 $ 88,366 Class A common stock: Basic net income available to common stockholders $ 25,663 $ 20,014 $ 72,200 $ 59,421 Basic weighted average common shares outstanding 27,512 27,139 27,421 27,071 Basic earnings per share $ 0.93 $ 0.74 $ 2.63 $ 2.19 Diluted net income available to common stockholders $ 25,754 $ 20,080 $ 72,495 $ 59,656 Effect of potential exercise of stock options 301 274 349 330 Diluted weighted average common shares outstanding 27,813 27,413 27,770 27,401 Diluted earnings per share $ 0.93 $ 0.73 $ 2.61 $ 2.18 Class B common stock: Basic net income available to common stockholders $ 12,293 $ 9,725 $ 34,693 $ 28,945 Basic weighted average common shares outstanding 13,177 13,187 13,177 13,187 Basic earnings per share $ 0.93 $ 0.74 $ 2.63 $ 2.19 Diluted net income available to common stockholders $ 12,202 $ 9,659 $ 34,398 $ 28,710 Diluted weighted average common shares outstanding 13,177 13,187 13,177 13,187 Diluted earnings per share $ 0.93 $ 0.73 $ 2.61 $ 2.18 For the three months ended September 30, 2021 and 2020, options to purchase 24,926 shares and 201,880 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, 2021 and 2020, options to purchase 8,673 shares and 221,845 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, 2021 and 2020, there were 163,577 shares and 127,467 shares, respectively, issued from the exercise of stock options. For the nine months ended September 30, 2021 and 2020 there were 135,349 shares and 54,433 shares, respectively, issued from the vesting of restricted stock units.

Property and Equipment (Notes)

Property and Equipment (Notes)	9 Months Ended
	Sep. 30, 2021
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 $ 222,857 $ 194,470 Leasehold improvements 69,031 62,293 Finance leases 796 705 Property and equipment—gross 292,684 257,468 Accumulated depreciation and amortization (165,642) (136,172) Property and equipment—net $ 127,042 $ 121,296

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets (Notes)	9 Months Ended
	Sep. 30, 2021
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, 2020 and nine months ended September 30, 2021 are as follows (in thousands): Goodwill Balance Goodwill at December 31, 2019 $ 1,191,259 Acquisitions 46,624 Acquisition fair value adjustment 11 Goodwill at December 31, 2020 1,237,894 Acquisition fair value adjustment 196 Goodwill at September 30, 2021 $ 1,238,090 Other intangible assets consisted of the following (in thousands): September 30, 2021 December 31, 2020 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Other intangible assets: Contract and program intangible assets $ 430,632 $ 256,859 $ 173,773 $ 430,632 $ 242,194 $ 188,438 Capitalized software 54,570 46,109 8,461 54,605 40,812 13,793 Total other intangible assets—net $ 485,202 $ 302,968 $ 182,234 $ 485,237 $ 283,006 $ 202,231 Amortization expense relating to intangible assets for the three months ended September 30, 2021 and 2020 was $6.9 million and $8.2 million, respectively. Amortization expense relating to intangible assets for the nine months ended September 30, 2021 and 2020 was $20.0 million and $21.2 million, respectively. Amortization expense for the nine months ended September 30, 2021 includes an impairment of $1.2 million for capitalized software. 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, 2021 $ 5,730 For the year ending: December 31, 2022 $ 23,448 December 31, 2023 $ 19,283 December 31, 2024 $ 17,486 December 31, 2025 $ 15,423 December 31, 2026 $ 14,331

Debt (Notes)

Debt (Notes)	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Debt [Text Block]	DebtOn July 20, 2021, we amended and restated our credit agreement (Third Amended and Restated Credit Agreement) with a syndicate of lenders led by Bank of America, N.A., as sole administrative agent. The Third Amended and Restated Credit Agreement includes an aggregate principal amount of up to $1.1 billion made available through (i) a $500 million revolving credit facility with a $100 million letter of credit sublimit and a $50 million swing line loan sublimit and (ii) a $600 million delayed-draw term loan facility. Under the delayed-draw term loan facility, borrowings are available to be drawn prior to the first anniversary of the Third Amended and Restated Credit Agreement in up to three separate drawings in a minimal amount of $50 million. The Third Amended and Restated Credit Agreement also includes an accordion feature that permits us to arrange with the lenders for the provision of additional commitments. The maturity date of the Third Amended and Restated Credit Agreement is July 20, 2026. We have deferred $3.7 million in debt issuance costs, including $3.3 million due to the Third Amended and Restated Credit Agreement, which are being amortized over the term of the new credit agreement. Borrowings under the Third Amended and Restated Credit Agreement are collateralized by substantially all of our assets and those of our Material Subsidiaries 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 2.00% based on our consolidated total leverage ratio) or Bank of America's base rate plus market spreads (0.25% to 1.00% based on our consolidated total leverage ratio). The terms of the Third Amended and Restated Credit Agreement permit prepayment and termination of the loan commitments at any time, subject to certain conditions. The Third Amended and Restated Credit Agreement requires us to comply with specified financial covenants, including the maintenance of certain leverage ratios and a consolidated coverage ratio. The Third Amended and Restated 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, 2021 and 2020, we were in compliance with these covenants.

Commitments and Contingencies (

Commitments and Contingencies (Notes)	9 Months Ended
	Sep. 30, 2021
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 2018 with no material adjustments. The remaining audits for 2019 through 2020 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. We believe that the ultimate resolution of these matters will not have a material effect on our financial position, results of operations or cash flows. We have $2.1 million outstanding on our letter of credit, of which $1.6 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, 2021
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), among others. 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, 2021, there were 607,066 additional shares made available for issuance under the Plan. Through September 30, 2021, the Board of Directors has authorized the issuance of up to 16,358,071 shares under this Plan. Through September 30, 2021, the remaining aggregate number of shares of our common stock available for future grants under the Plan was 7,684,850. 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, 2021 and 2020, we recorded $3.9 million and $3.0 million, respectively, of stock-based compensation expense. For the nine months ended September 30, 2021 and 2020, we recorded $11.5 million and $8.5 million, respectively, 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, 2021 and 2020, we recorded $0.4 million and $0.2 million, respectively, to income tax 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, 2021 and 2020, we recorded $1.9 million and $1.0 million, respectively, to income tax 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 in the past. 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 did not grant any options during the nine months ended September 30, 2021 and year ended December 31, 2020. 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. Option grants that vested during the nine months ended September 30, 2021 and 2020 had a combined fair value of $1.1 million and $1.8 million, respectively. The following table summarizes stock option activity for the year ended December 31, 2020 and the nine months ended September 30, 2021: Number of Shares Weighted Average Exercise Price Aggregate Intrinsic Value Weighted Average Remaining Contractual Life Stock options outstanding at December 31, 2019 1,136,095 $ 54.98 $ 28,291 Exercised (223,405) $ 46.72 $ 6,897 Cancelled and expired (126,863) $ 61.17 Stock options outstanding at December 31, 2020 785,827 $ 56.33 $ 25,629 Exercised (163,577) $ 47.89 $ 6,270 Cancelled and expired (14,800) $ 63.50 Stock options outstanding at September 30, 2021 607,450 $ 58.42 $ 10,628 2 years Stock options exercisable at September 30, 2021 380,122 $ 54.37 $ 8,191 2 years The following table summarizes non-vested stock options for the nine months ended September 30, 2021: Number of Shares Weighted Average Fair Value Non-vested stock options at December 31, 2020 353,643 $ 11.66 Vested (113,516) $ 10.06 Cancelled (12,799) $ 12.27 Non-vested stock options at September 30, 2021 227,328 $ 12.43 Unrecognized compensation expense related to non-vested awards was $1.2 million as of September 30, 2021, which is expected to be recognized over a weighted-average period of 1 year. 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. The following table summarizes the restricted stock activity during the year ended December 31, 2020 and the nine months ended September 30, 2021: Number of Shares Weighted Average Fair Value Non-vested restricted stock at December 31, 2019 24,000 $ 62.66 Granted 24,000 $ 71.11 Vested (24,000) $ 62.66 Non-vested restricted stock at December 31, 2020 24,000 $ 71.11 Granted 24,000 $ 86.01 Vested (24,000) $ 71.11 Non-vested restricted stock at September 30, 2021 24,000 $ 86.01 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' time-based RSUs generally provide for the delivery of shares 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. The following table summarizes the non-vested RSU activity during the year ended December 31, 2020 and the nine months ended September 30, 2021: Number of Units Weighted Average Fair Value Non-vested RSUs at December 31, 2019 210,827 $ 55.31 Granted 266,880 $ 68.83 Vested (73,047) $ 53.85 Forfeited (57,861) $ 64.52 Non-vested RSUs at December 31, 2020 346,799 $ 64.48 Granted 197,670 $ 78.62 Vested (111,349) $ 61.75 Forfeited (17,005) $ 63.95 Non-vested RSUs at September 30, 2021 416,115 $ 71.95

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2021
Subsequent Events [Abstract]
Subsequent Events	Subsequent EventsOn October 29, 2021, the Company entered into a Unit Purchase Agreement by and among the Company, Gryphon Parent, LLC and Gryphon Finance, LLC to acquire Gryphon Technologies, Inc. in exchange for $350 million. We believe the acquisition of Gryphon Technologies, Inc. will further strengthen our long-term competitive position by adding differentiated digital and systems engineering capabilities across the Department of Defense. The transaction is subject to the Hart-Scott-Rodino Act and is expected to close within the fourth quarter of 2021.

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Tables)	9 Months Ended
	Sep. 30, 2021
Revenue from Contract with Customer [Abstract]
Revenue by Contract Type [Table Text Block]	Three months ended Nine months ended 2021 2020 2021 2020 Cost-reimbursable $ 441,588 $ 431,991 $ 1,305,313 $ 1,283,522 Fixed-price 113,122 126,402 362,804 368,316 Time-and-materials 83,111 77,803 251,506 227,762 Revenue $ 637,821 $ 636,196 $ 1,919,623 $ 1,879,600
Revenue by Customer [Table Text Block]	Three months ended Nine months ended 2021 2020 2021 2020 U.S. Government $ 631,765 $ 624,888 $ 1,903,018 $ 1,848,043 State agencies, international agencies and commercial entities 6,056 11,308 16,605 31,557 Revenue $ 637,821 $ 636,196 $ 1,919,623 $ 1,879,600
Revenue by Contractor Type [Table Text Block]	Three months ended Nine months ended 2021 2020 2021 2020 Prime contractor $ 596,420 $ 579,858 $ 1,787,800 $ 1,712,403 Subcontractor 41,401 56,338 131,823 167,197 Revenue $ 637,821 $ 636,196 $ 1,919,623 $ 1,879,600
Schedule Of Contract Receivables [Table Text Block]	The components of our receivables are as follows (in thousands): September 30, 2021 December 31, 2020 Billed receivables $ 313,336 $ 312,991 Unbilled receivables 91,251 106,007 Allowance for doubtful accounts (15,184) (18,377) Receivables—net $ 389,403 $ 400,621
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, 2021 For the year ending December 31, 2022 December 31, 2023 Thereafter $ 0.6 $ 1.0 $ 0.2 $ 0.4

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2021
Leases [Abstract]
Lessee, Lease, Balance Sheet	The balance sheet information related to our operating leases was as follows (dollars in thousands): September 30, 2021 December 31, 2020 Operating Leases Operating lease right of use assets $ 79,266 $ 94,825 Operating lease obligations—current $ 31,291 $ 30,105 Operating lease obligations—long term $ 67,306 $ 80,242
Lease, Cost	The components of operating lease expense are as follows: Three months ended Nine months ended 2021 2020 2021 2020 Operating lease expense $ 12,004 $ 8,465 $ 28,907 $ 25,548

Acquisitions (Tables)

Acquisitions (Tables)	9 Months Ended
	Sep. 30, 2021
Tapestry Technologies
Business Combination Segment Allocation [Line Items]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block]	The following table represents the purchase price allocation for Tapestry (in thousands): Cash and cash equivalents $ 36 Receivables 3,926 Prepaid expenses 225 Goodwill 27,013 Other intangible assets 16,500 Property and equipment 269 Operating lease right of use assets 934 Other assets 10 Accounts payable (522) Accrued salaries and related expenses (1,142) Operating lease obligations—current (487) Accrued expenses and other current liabilities (59) Operating lease obligations—long term (453) Net assets acquired and liabilities assumed $ 46,250
Minerva Engineering
Business Combination Segment Allocation [Line Items]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block]	The following table represents the preliminary purchase price allocation for Minerva (in thousands): Cash and cash equivalents $ 56 Receivables 4,181 Prepaid expenses 28 Goodwill 19,807 Other intangible assets 11,600 Property and equipment 149 Operating lease right of use assets 968 Other assets 29 Accounts payable (1,875) Accrued salaries and related expenses (784) Operating lease obligations—current (384) Accrued expenses and other current liabilities (555) Operating lease obligations—long term (562) Net assets acquired and liabilities assumed $ 32,658

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2021
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 2021 2020 2021 2020 Distributed earnings $ 15,475 $ 12,915 $ 46,326 $ 38,685 Undistributed earnings 22,481 16,824 60,567 49,681 Net income $ 37,956 $ 29,739 $ 106,893 $ 88,366 Class A common stock: Basic net income available to common stockholders $ 25,663 $ 20,014 $ 72,200 $ 59,421 Basic weighted average common shares outstanding 27,512 27,139 27,421 27,071 Basic earnings per share $ 0.93 $ 0.74 $ 2.63 $ 2.19 Diluted net income available to common stockholders $ 25,754 $ 20,080 $ 72,495 $ 59,656 Effect of potential exercise of stock options 301 274 349 330 Diluted weighted average common shares outstanding 27,813 27,413 27,770 27,401 Diluted earnings per share $ 0.93 $ 0.73 $ 2.61 $ 2.18 Class B common stock: Basic net income available to common stockholders $ 12,293 $ 9,725 $ 34,693 $ 28,945 Basic weighted average common shares outstanding 13,177 13,187 13,177 13,187 Basic earnings per share $ 0.93 $ 0.74 $ 2.63 $ 2.19 Diluted net income available to common stockholders $ 12,202 $ 9,659 $ 34,398 $ 28,710 Diluted weighted average common shares outstanding 13,177 13,187 13,177 13,187 Diluted earnings per share $ 0.93 $ 0.73 $ 2.61 $ 2.18

Property and Equipment (Tables)

Property and Equipment (Tables)	9 Months Ended
	Sep. 30, 2021
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 $ 222,857 $ 194,470 Leasehold improvements 69,031 62,293 Finance leases 796 705 Property and equipment—gross 292,684 257,468 Accumulated depreciation and amortization (165,642) (136,172) Property and equipment—net $ 127,042 $ 121,296

Goodwill and Other Intangible_2

Goodwill and Other Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2021
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, 2020 and nine months ended September 30, 2021 are as follows (in thousands): Goodwill Balance Goodwill at December 31, 2019 $ 1,191,259 Acquisitions 46,624 Acquisition fair value adjustment 11 Goodwill at December 31, 2020 1,237,894 Acquisition fair value adjustment 196 Goodwill at September 30, 2021 $ 1,238,090
Schedule of Other Intangible Assets [Table Text Block]	Other intangible assets consisted of the following (in thousands): September 30, 2021 December 31, 2020 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Other intangible assets: Contract and program intangible assets $ 430,632 $ 256,859 $ 173,773 $ 430,632 $ 242,194 $ 188,438 Capitalized software 54,570 46,109 8,461 54,605 40,812 13,793 Total other intangible assets—net $ 485,202 $ 302,968 $ 182,234 $ 485,237 $ 283,006 $ 202,231
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, 2021 $ 5,730 For the year ending: December 31, 2022 $ 23,448 December 31, 2023 $ 19,283 December 31, 2024 $ 17,486 December 31, 2025 $ 15,423 December 31, 2026 $ 14,331

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Payment Arrangement, Option, Activity [Table Text Block]	The following table summarizes stock option activity for the year ended December 31, 2020 and the nine months ended September 30, 2021: Number of Shares Weighted Average Exercise Price Aggregate Intrinsic Value Weighted Average Remaining Contractual Life Stock options outstanding at December 31, 2019 1,136,095 $ 54.98 $ 28,291 Exercised (223,405) $ 46.72 $ 6,897 Cancelled and expired (126,863) $ 61.17 Stock options outstanding at December 31, 2020 785,827 $ 56.33 $ 25,629 Exercised (163,577) $ 47.89 $ 6,270 Cancelled and expired (14,800) $ 63.50 Stock options outstanding at September 30, 2021 607,450 $ 58.42 $ 10,628 2 years Stock options exercisable at September 30, 2021 380,122 $ 54.37 $ 8,191 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, 2021: Number of Shares Weighted Average Fair Value Non-vested stock options at December 31, 2020 353,643 $ 11.66 Vested (113,516) $ 10.06 Cancelled (12,799) $ 12.27 Non-vested stock options at September 30, 2021 227,328 $ 12.43
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, 2020 and the nine months ended September 30, 2021: Number of Shares Weighted Average Fair Value Non-vested restricted stock at December 31, 2019 24,000 $ 62.66 Granted 24,000 $ 71.11 Vested (24,000) $ 62.66 Non-vested restricted stock at December 31, 2020 24,000 $ 71.11 Granted 24,000 $ 86.01 Vested (24,000) $ 71.11 Non-vested restricted stock at September 30, 2021 24,000 $ 86.01
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, 2020 and the nine months ended September 30, 2021: Number of Units Weighted Average Fair Value Non-vested RSUs at December 31, 2019 210,827 $ 55.31 Granted 266,880 $ 68.83 Vested (73,047) $ 53.85 Forfeited (57,861) $ 64.52 Non-vested RSUs at December 31, 2020 346,799 $ 64.48 Granted 197,670 $ 78.62 Vested (111,349) $ 61.75 Forfeited (17,005) $ 63.95 Non-vested RSUs at September 30, 2021 416,115 $ 71.95

Revenue from Contracts with C_3

Revenue from Contracts with Customers Narrative (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021USD ($)	Sep. 30, 2020USD ($)	Sep. 30, 2021USD ($)Entities	Sep. 30, 2020USD ($)	Dec. 31, 2020USD ($)
Revenue from Contract with Customers [Line Items]
Contract with Customer, Asset, Cumulative Catch-up Adjustment to Revenue, Change in Measure of Progress	$ 3,700	$ 4,300	$ 8,100	$ 9,400
Number of Reportable Segments | Entities			1
Contract Receivable, Due after Next Rolling Twelve Months	4,100		$ 4,100
Contract with Customer, Liability, Current	34,442		34,442		$ 37,218
Contract with Customer, Liability, Revenue Recognized	1,200		30,600
Revenue, Remaining Performance Obligation, Amount	$ 2,200,000		$ 2,200,000
UNITED STATES | Revenue from Contract with Customer, Segment Benchmark [Member] | Geographic Concentration Risk
Revenue from Contract with Customers [Line Items]
Concentration Risk, Percentage	100.00%	99.00%	100.00%	99.00%

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, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Revenue by Contract Type [Line Items]
Revenue	$ 637,821	$ 636,196	$ 1,919,623	$ 1,879,600
Cost-reimbursable
Revenue by Contract Type [Line Items]
Revenue	441,588	431,991	1,305,313	1,283,522
Fixed-price
Revenue by Contract Type [Line Items]
Revenue	113,122	126,402	362,804	368,316
Time-and-materials
Revenue by Contract Type [Line Items]
Revenue	$ 83,111	$ 77,803	$ 251,506	$ 227,762

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, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Revenue from External Customer [Line Items]
Revenue	$ 637,821	$ 636,196	$ 1,919,623	$ 1,879,600
U.S. Government
Revenue from External Customer [Line Items]
Revenue	631,765	624,888	1,903,018	1,848,043
State agencies, international agencies and commercial entities
Revenue from External Customer [Line Items]
Revenue	$ 6,056	$ 11,308	$ 16,605	$ 31,557

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, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Revenue by Contractor Type [Line Items]
Revenue	$ 637,821	$ 636,196	$ 1,919,623	$ 1,879,600
Prime contractor
Revenue by Contractor Type [Line Items]
Revenue	596,420	579,858	1,787,800	1,712,403
Subcontractor
Revenue by Contractor Type [Line Items]
Revenue	$ 41,401	$ 56,338	$ 131,823	$ 167,197

Revenue from Contracts with C_7

Revenue from Contracts with Customers Schedule of Contract Receivables (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Billed receivables	$ 313,336	$ 312,991
Unbilled receivables	91,251	106,007
Allowance for doubtful accounts	(15,184)	(18,377)
Receivables—net	$ 389,403	$ 400,621

Revenue from Contracts with C_8

Revenue from Contracts with Customers Revenue, Remaining Performance Obligation (Details) $ in Billions	Sep. 30, 2021USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 2.2
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 0.6
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	3 months
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, Amount	$ 1
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 0.2
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 0.4
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period

Leases Balance Sheet Informatio

Leases Balance Sheet Information (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Operating Leases [Abstract]
Operating lease right of use assets	$ 79,266	$ 94,825
Operating lease obligations—current	31,291	30,105
Operating lease obligations—long term	$ 67,306	$ 80,242

Leases Cost (Details)

Leases Cost (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Leases [Abstract]
Operating lease expense	$ 12,004	$ 8,465	$ 28,907	$ 25,548

Leases Narrative (Details)

Leases Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Operating Lease, Cost	$ 12,004	$ 8,465	$ 28,907	$ 25,548
Disposal Group, Disposed of by Means Other than Sale, Not Discontinued Operations, Abandonment
Operating Lease, Cost	$ 3,400		$ 3,400

Acquisitions Narrative (Details

Acquisitions Narrative (Details) $ in Millions	9 Months Ended
	Sep. 30, 2021USD ($)
Tapestry Technologies
Business Combination, Consideration Transferred	$ 46.3
Expected Goodwill Tax Amortization Period	15 years
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	18 years
Tapestry Technologies | Customer Relationships [Member]
Finite-Lived Intangible Assets Acquired	$ 15.1
Finite-Lived Intangible Asset, Useful Life	20 years
Tapestry Technologies | Backlog [Member]
Finite-Lived Intangible Assets Acquired	$ 1.4
Finite-Lived Intangible Asset, Useful Life	2 years
Minerva Engineering
Business Combination, Consideration Transferred	$ 32.7
Expected Goodwill Tax Amortization Period	15 years
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	18 years
Minerva Engineering | Customer Relationships [Member]
Finite-Lived Intangible Assets Acquired	$ 10.5
Finite-Lived Intangible Asset, Useful Life	20 years
Minerva Engineering | Backlog [Member]
Finite-Lived Intangible Assets Acquired	$ 1.1
Finite-Lived Intangible Asset, Useful Life	2 years

Acquisitions Schedule of Purcha

Acquisitions Schedule of Purchase Price Allocation (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Business Acquisition [Line Items]
Goodwill	$ 1,238,090	$ 1,237,894	$ 1,191,259
Tapestry Technologies
Business Acquisition [Line Items]
Cash and cash equivalents	36
Receivables	3,926
Prepaid expenses	225
Goodwill	27,013
Other intangible assets	16,500
Property and equipment	269
Operating lease right of use assets	934
Other assets	10
Accounts payable	(522)
Accrued salaries and related expenses	(1,142)
Operating lease obligations—current	(487)
Accrued expenses and other current liabilities	(59)
Operating lease obligations—long term	(453)
Net assets acquired and liabilities assumed	46,250
Minerva Engineering
Business Acquisition [Line Items]
Cash and cash equivalents	56
Receivables	4,181
Prepaid expenses	28
Goodwill	19,807
Other intangible assets	11,600
Property and equipment	149
Operating lease right of use assets	968
Other assets	29
Accounts payable	(1,875)
Accrued salaries and related expenses	(784)
Operating lease obligations—current	(384)
Accrued expenses and other current liabilities	(555)
Operating lease obligations—long term	(562)
Net assets acquired and liabilities assumed	$ 32,658

Earnings Per Share (Narrative)

Earnings Per Share (Narrative) (Details) - $ / shares	3 Months Ended						9 Months Ended		12 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Earnings Per Share [Abstract]
Common Stock, Dividends, Per Share, Cash Paid	$ 0.38	$ 0.38	$ 0.38	$ 0.32	$ 0.32	$ 0.32
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	24,926			201,880			8,673	221,845
Exercised, Number of Shares							(163,577)	(127,467)	(223,405)
Stock Issued During Period, Shares, Restricted Stock Vesting							135,349	54,433

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, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Components of Earnings Per Share, Basic and Diluted [Line Items]
Distributed earnings	$ 15,475	$ 12,915	$ 46,326	$ 38,685
Undistributed earnings	22,481	16,824	60,567	49,681
Net income	37,956	29,739	106,893	88,366
Class A common stock
Components of Earnings Per Share, Basic and Diluted [Line Items]
Basic net income available to common stockholders	$ 25,663	$ 20,014	$ 72,200	$ 59,421
Basic weighted average common shares outstanding	27,512	27,139	27,421	27,071
Basic earnings per share	$ 0.93	$ 0.74	$ 2.63	$ 2.19
Diluted net income available to common stockholders	$ 25,754	$ 20,080	$ 72,495	$ 59,656
Effect of potential exercise of stock options	301	274	349	330
Diluted weighted average common shares outstanding	27,813	27,413	27,770	27,401
Diluted earnings per share	$ 0.93	$ 0.73	$ 2.61	$ 2.18
Class B common stock
Components of Earnings Per Share, Basic and Diluted [Line Items]
Basic net income available to common stockholders	$ 12,293	$ 9,725	$ 34,693	$ 28,945
Basic weighted average common shares outstanding	13,177	13,187	13,177	13,187
Basic earnings per share	$ 0.93	$ 0.74	$ 2.63	$ 2.19
Diluted net income available to common stockholders	$ 12,202	$ 9,659	$ 34,398	$ 28,710
Diluted weighted average common shares outstanding	13,177	13,187	13,177	13,187
Diluted earnings per share	$ 0.93	$ 0.73	$ 2.61	$ 2.18

Property and Equipment (Propert

Property and Equipment (Property and Equipment) (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Furniture and equipment	$ 222,857	$ 194,470
Leasehold improvements	69,031	62,293
Finance leases	796	705
Property and equipment—gross	292,684	257,468
Accumulated depreciation and amortization	(165,642)	(136,172)
Property and equipment—net	$ 127,042	$ 121,296

Property and Equipment Narrativ

Property and Equipment Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Property, Plant and Equipment [Abstract]
Depreciation and amortization expense related to property and equipment	$ 11.7	$ 9.2	$ 34.9	$ 27.7

Goodwill and Other Intangible_3

Goodwill and Other Intangible Assets (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Finite-Lived Intangible Assets [Line Items]
Amortization of Intangible Assets	$ 6.9	$ 8.2	$ 20	$ 21.2
Capitalized software
Finite-Lived Intangible Assets [Line Items]
Impairment of Intangible Assets, Finite-lived			$ 1.2

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, 2021	Dec. 31, 2020
Goodwill [Roll Forward]
Goodwill	$ 1,237,894	$ 1,191,259
Acquisitions		46,624
Acquisition fair value adjustment	196	11
Goodwill	$ 1,238,090	$ 1,237,894

Goodwill and Other Intangible_5

Goodwill and Other Intangible Assets (Schedule of Other Intangible Assets) (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 485,202	$ 485,237
Accumulated Amortization	302,968	283,006
Net Carrying Amount	182,234	202,231
Contract and program intangible assets
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	430,632	430,632
Accumulated Amortization	256,859	242,194
Net Carrying Amount	173,773	188,438
Capitalized software
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	54,570	54,605
Accumulated Amortization	46,109	40,812
Net Carrying Amount	$ 8,461	$ 13,793

Goodwill and Other Intangible_6

Goodwill and Other Intangible Assets (Schedule of Other Intangible Assets, Future Amortization Expense) (Details) $ in Thousands	Sep. 30, 2021USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
For the remaining three months ending December 31, 2021	$ 5,730
For the year ending:
December 31, 2022	23,448
December 31, 2023	19,283
December 31, 2024	17,486
December 31, 2025	15,423
December 31, 2026	$ 14,331

Debt (Revolving Credit Facility

Debt (Revolving Credit Facility) (Narrative) (Details) - USD ($)	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Line of Credit Facility [Line Items]
Debt Issuance Costs, Line of Credit Arrangements, Net	$ 3,700,000
Payments of Debt Issuance Costs	3,315,000	$ 0
Long-term Line of Credit	0		$ 15,000,000
Bank of America Syndicate [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	1,100,000,000
Long-term Line of Credit	0		$ 15,000,000
Line of Credit Facility, Remaining Borrowing Capacity	1,100,000,000
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
Bank of America Syndicate [Member] | Letter of Credit [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	100,000,000
Contingent Liability under Letters of Credit	2,100,000
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	50,000,000
Bank of America Syndicate [Member] | Term Loan Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	600,000,000
Line Of Credit Facility, Minimum Borrowing Capacity	$ 50,000,000
London Interbank Offered Rate (LIBOR) [Member] | Bank of America Syndicate [Member] | Minimum [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.25%
London Interbank Offered Rate (LIBOR) [Member] | Bank of America Syndicate [Member] | Maximum [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	2.00%
Bank of America's Base Rate [Member] | Bank of America Syndicate [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] | Bank of America Syndicate [Member] | Maximum [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.00%

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, 2021USD ($)
Line of Credit Facility [Line Items]
Letters of Credit Outstanding, Amount	$ 2.1
Performance Guarantee [Member]
Line of Credit Facility [Line Items]
Letters of Credit Outstanding, Amount	$ 1.6

Stock-Based Compensation (Narra

Stock-Based Compensation (Narrative) (Details) - USD ($)	Jan. 02, 2021	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
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	607,066
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized		16,358,071		16,358,071
Remaining Aggregate Number of Shares Available For Issuance		7,684,850		7,684,850
Share-based Compensation		$ 3,900,000	$ 3,000,000	$ 11,500,000	$ 8,500,000
Share-based Payment Arrangement, Amount Capitalized				0	0
Share-based Payment Arrangement, Expense, Tax Benefit		(400,000)	$ (200,000)	(1,900,000)	(1,000,000)
Share-based Payment Award, Options, Vested, Fair Value				1,100,000	$ 1,800,000
Share-based Compensation, Nonvested Awards, Total Compensation Cost Not Yet Recognized		$ 1,200,000		$ 1,200,000
Share-based Compensation, Nonvested Awards, Total Compensation Cost Not Yet Recognized, Period for Recognition				1 year
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

Stock-Based Compensation (Sched

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, 2021	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Share-based Payment Award, Options, Outstanding [Roll Forward]
Stock options, Number of Shares, Period Start	785,827	1,136,095	1,136,095
Exercised, Number of Shares	(163,577)	(127,467)	(223,405)
Cancelled and expired, Number of Shares	(14,800)		(126,863)
Stock options, Number of Shares, Period End	607,450		785,827
Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Stock options, Weighted Average Exercise Price, Period Start	$ 56.33	$ 54.98	$ 54.98
Exercised, Weighted Average Exercise Price	47.89		46.72
Cancelled and expired, Weighted Average Exercise Price	63.50		61.17
Stock options, Weighted Average Exercise Price, Period End	$ 58.42		$ 56.33
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Stock options outstanding, Aggregate Intrinsic Value	$ 10,628		$ 25,629	$ 28,291
Exercised, Aggregate Intrinsic Value	$ 6,270		$ 6,897
Stock options outstanding, Weighted Average Remaining Contractual Life	2 years
Stock options exercisable, Number of Shares	380,122
Stock options exercisable, Weighted Average Exercise Price	$ 54.37
Stock options exercisable, Aggregate Intrinsic Value	$ 8,191
Stock options exercisable, Weighted Average Remaining Contractual Life	2 years

Stock-Based Compensation (Sch_2

Stock-Based Compensation (Schedule of Non-vested Share Activity) (Details)	9 Months Ended
	Sep. 30, 2021$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Non-vested [Roll Forward]
Non-vested stock options, Number of Shares, Period Start | shares	353,643
Vested, Number of Shares | shares	(113,516)
Cancelled, Number of Shares | shares	(12,799)
Non-vested stock options, Number of Shares, Period End | shares	227,328
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 | $ / shares	$ 11.66
Vested, Weighted Average Fair Value | $ / shares	10.06
Cancelled, Weighted Average Fair Value | $ / shares	12.27
Non-vested stock options, Weighted Average Fair Value, Period End | $ / shares	$ 12.43

Stock-Based Compensation (Sch_3

Stock-Based Compensation (Schedule Of Share-based Compensation, Restricted Stock Activity) (Details) - Restricted Stock [Member] - $ / shares	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award, Restricted Stock, Non-vested [Roll Forward]
Non-vested, Period Start	24,000	24,000
Granted	24,000	24,000
Vested	(24,000)	(24,000)
Non-vested, Period End	24,000	24,000
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	$ 71.11	$ 62.66
Granted, Weighted Average Fair Value	86.01	71.11
Vested, Weighted Average Fair Value	71.11	62.66
Non-vested, Weighted Average Fair Value, Period End	$ 86.01	$ 71.11

Stock-Based Compensation (Sch_4

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, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award, Restricted Stock Units, Nonvested, Number of Shares [Roll Forward]
Non-vested, Period Start	346,799	210,827
Granted	197,670	266,880
Vested	(111,349)	(73,047)
Forfeited	(17,005)	(57,861)
Non-vested, Period End	416,115	346,799
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	$ 64.48	$ 55.31
Granted, Weighted Average Fair Value	78.62	68.83
Vested, Weighted Average Fair Value	61.75	53.85
Forfeited, Weighted Average Fair Value	63.95	64.52
Non-vested, Weighted Average Fair Value, Period End	$ 71.95	$ 64.48

Subsequent Events (Details)

Subsequent Events (Details)	Oct. 29, 2021USD ($)
Subsequent Event | Gryphon Technologies
Subsequent Event [Line Items]
Business Combination, Consideration Transferred	$ 350,000,000