Significant Accounting Policies and Practices (Policies)	3 Months Ended
Mar. 31, 2023
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited Condensed Consolidated Financial Statements of the Company have been prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”) for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, certain information and disclosures normally included in the financial statements have been condensed or omitted as permitted by such rules and regulations. All adjustments (consisting only of adjustments of a normal and recurring nature) considered necessary for a fair presentation have been included. Operating results during the three months ended March 31, 2023 are not necessarily indicative of the results to be expected for any other interim period or the fiscal year ending December 31, 2023. The financial statements presented in this report should be read in conjunction with the Company’s annual Consolidated Financial Statements and notes thereto included in the Annual Report on Form 10-K for the year ended December 31, 2022 filed on February 24, 2023 with the Securities and Exchange Commission.
Principles of Consolidation	Principles of Consolidation The unaudited Condensed Consolidated Financial Statements include the accounts of the Company, its wholly owned subsidiaries, and Variable Interest Entities ("VIEs") in which the Company is the primary beneficiary. The Company is the primary beneficiary of a VIE when the Company has the power to direct activities that most significantly affect the economic performance of the VIE. If the Company is not the primary beneficiary in a VIE, the Company accounts for the investment in the VIE in accordance with applicable U.S. GAAP. As of March 31, 2023 and December 31, 2022, assets related to consolidated VIEs were $54.4 million and $57.1 million, respectively, which were primarily related to right-of-use (“ROU”) assets and property and equipment, net. As of March 31, 2023 and December 31, 2022, liabilities related to consolidated VIEs were $49.7 million and $50.9 million, respectively, which were primarily related to operating and finance lease liabilities. All intercompany profits, transactions and balances have been eliminated in consolidation.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash equivalents represent funds temporarily invested in money market instruments with maturities of three months or less. Cash equivalents are stated at cost, which approximates fair value. Cash and cash equivalents that are restricted as to withdrawal or use under the terms of certain contractual agreements were $0.7 million and $0.6 million as of March 31, 2023 and December 31, 2022, respectively, and were included in Cash and cash equivalents within the Condensed Consolidated Balance Sheets.
Allowance for Doubtful Accounts	Allowance for Doubtful Accounts Accounts receivable, net of the allowance for doubtful accounts, represents the Company’s estimate of the amount that ultimately will be realized in cash. The Company reviews the adequacy of its allowance for doubtful accounts on an ongoing basis, primarily using a review of specific accounts, as well as historical collection trends and aging of receivables, and records adjustments to the allowance as necessary. The Company’s allowance for doubtful accounts, which was included in Accounts receivable, net, within the Condensed Consolidated Balance Sheets, was $3.9 million and $4.0 million as of March 31, 2023 and December 31, 2022, respectively.
Property and Equipment, Net	Property and Equipment, Net Property and equipment includes the Company's equipment, internal-use software, vehicles, leasehold improvements and construction/development in process. Property and equipment are stated at cost, less accumulated depreciation and amortization, whenever applicable. Certain costs incurred in the planning and evaluation stage of internal-use software projects are recorded to expense as incurred. Costs associated with directly obtaining, developing or upgrading internal-use software are capitalized and included as Software in Property and equipment, net, within the Condensed Consolidated Balance Sheets. When the internal-use software is ready for its intended use, it is amortized on a straight-line basis over the estimated useful life of the internal-use software, which is typically 3 years. Equipment and vehicles are depreciated on a straight-line basis over the estimated useful lives ranging from 1 to 10 years. Expenditures for major renewals and improvements that extend the useful life of property and equipment are capitalized. Leasehold improvements are amortized on a straight-line basis over the terms of the respective leases or the useful lives of the improvements, whichever is shorter.
Equity Investments in Unconsolidated Entities	Equity Investments in Unconsolidated Entities The Company has ownership interests in 34 active partnerships, joint ventures or similar arrangements that operate parking facilities, of which 28 are consolidated under the VIE or voting interest models and 6 are unconsolidated where the Company’s ownership interests range from 30-50 percent and for which there are no indicators of control. The Company accounts for such investments under the equity method of accounting, and the Company’s underlying share of each investee’s equity of $12.1 million and $11.9 million as of March 31, 2023 and December 31, 2022, respectively, was included in Other noncurrent assets within the Condensed Consolidated Balance Sheets. As the operations of these entities are consistent with the Company’s underlying core business operations, the equity in earnings of these investments were included in Services revenue - lease type contracts within the Condensed Consolidated Statements of Income. The equity earnings in these related investments were $0.7 million and $0.9 million during the three months ended March 31, 2023 and 2022, respectively.
Other Noncurrent Assets	Other Noncurrent Assets Other noncurrent assets consisted of equity investments of unconsolidated entities, advances, deposits and cost of contracts, net, as of March 31, 2023 and December 31, 2022.
Accrued and Other Current Liabilities	Accrued and Other Current Liabilities Accrued and other current liabilities consisted of insurance, accrued rent, compensation, payroll withholdings, property, payroll and other taxes and other accrued expenses as of March 31, 2023 and December 31, 2022.
Noncontrolling Interests	Noncontrolling Interests Noncontrolling interests represent the noncontrolling holders’ percentage share of income (losses) from the subsidiaries in which the Company holds a controlling interest, but less than 100 percent, ownership interest. The results of these subsidiaries are consolidated and included within the Condensed Consolidated Financial Statements. During the three months ended March 31, 2023, the Company recorded a $1.0 million liability related to its estimate of additional consideration (“contingent consideration") due to a former minority partner that formerly held a noncontrolling interest in a joint venture with the Company. The Company purchased the minority partner’s interest in the joint venture in 2020. The contingent consideration is contingent on the performance of the operations of the Bradley International Airport. The contingent consideration is not capped and, if any amount is due, would be payable to the former minority partner in April 2025. The $1.0 million was determined based on a probability weighting of potential payouts and recorded in Additional paid-in capital within the Condensed Consolidated Balance Sheets. In addition, the Company recorded a deferred tax asset of $0.3 million related to the contingent consideration during the three months ended March 31, 2023, which was recorded in Additional paid-in capital within the Condensed Consolidated Balance Sheets. The Company will continue to evaluate the criteria for making these payments in the future and adjust the liability when deemed necessary. Additionally, during the three months ended March 31, 2023, the Company paid a former minority partner $2.1 million per the terms of an agreement between the Company and the former minority partner. The Company purchased the former minority partner’s entire noncontrolling interest in a joint venture with the Company as of December 31, 2022. Per the terms of the agreement, the Company will be required to make additional payments to the former minority partner over a ten-year period, amounting to a total of $4.5 million. The $2.1 million that was paid during the three months ended March 31, 2023 was included in Accrued and other current liabilities within the Condensed Consolidated Balance Sheets as of December 31, 2022.
Goodwill	Goodwill Goodwill represents the excess of the purchase price paid over the fair value of net assets acquired. In accordance with the Financial Accounting Standards Board's ("FASB") authoritative accounting guidance on goodwill, the Company evaluates goodwill for impairment on an annual basis, or more often if events or circumstances change that could cause goodwill to become impaired. The Company has elected to assess the impairment of goodwill annually on October 1 or at an interim date if there is an event or change in circumstances indicating the carrying value may not be recoverable. The goodwill impairment test is performed at the reporting unit level; the Company's reporting units represent its operating segments, consisting of Commercial and Aviation. Factors that could trigger an impairment review include significant under-performance relative to expected historical or projected future operating results, significant changes in the use of acquired assets or the Company’s business strategy, and significant negative industry or economic trends. The Company may perform a qualitative, rather than quantitative, assessment to determine whether it is more likely than not the fair value of a reporting unit is less than its carrying amount. If the Company determines impairment is present, the Company would need to perform a quantitative assessment. The determination of fair value of a reporting unit utilizes cash flow projections that assume certain future revenue and cost levels, comparable marketplace data, comparable company market valuations, assumed discount rates based upon current market conditions and other valuation factors, all of which involve the use of significant judgment and estimates. The Company also assesses critical areas that may impact its business, including economic conditions, market related exposures, competition, changes in service offerings and changes in key personnel.
Other Intangible Assets, Net	Other Intangible Assets, net Other intangible assets represent assets with finite lives that are amortized on a straight-line basis over their estimated useful lives. The Company evaluates other intangible assets on a periodic basis to determine whether events or circumstances warrant a revision to their remaining useful lives. In addition, other intangible assets are reviewed for impairment when circumstances change that would indicate the carrying value may not be recoverable. Assumptions and estimates about future values and remaining useful lives of intangible assets are complex and subjective, and can be affected by a variety of factors, including external factors such as industry and economic trends, and internal factors, such as changes in the Company's business strategy and forecasts. Although the Company believes the historical assumptions and estimates are reasonable and appropriate, different assumptions and estimates could materially impact reported financial results.
Long-Lived Assets	Long-Lived Assets The Company evaluates long-lived assets, including ROU assets, leasehold improvements, equipment and construction/development in progress, for impairment whenever events or circumstances indicate that the carrying value of an asset or asset group may not be recoverable. The Company groups assets at the lowest level for which cash flows are separately identified in order to measure an impairment. Events or circumstances that would result in an impairment review include a significant change in the use of an asset, the planned sale or disposal of an asset, or a projection that demonstrates continuing losses associated with the use of a long-lived asset or asset group. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of the asset or asset group to future undiscounted cash flows expected to be generated by the asset or asset group. If the asset or asset group is determined to be impaired, the impairment recognized is measured by the amount by which the carrying value of the asset or asset group exceeds its fair value. Assumptions and estimates used to determine cash flows in the evaluation of impairment and the fair values used to determine the impairment are subject to a degree of judgment and complexity. Any future changes to the assumptions and estimates resulting from changes in actual results or market conditions from those anticipated may affect the carrying value of long-lived assets or asset groups and could result in impairment charges. Future events that may result in impairment charges include economic volatility or other factors that could decrease revenues and profitability of existing locations and changes in the cost structure of existing facilities, such as increasing labor and benefit costs.
Foreign Operations	Foreign Operations The Company has foreign operations in Canada, Puerto Rico, the United Kingdom and India. Assets and liabilities of the Company’s foreign operations are translated into U.S. dollars at the rate in effect on the respective balance sheet date, while income and expenses are translated at the average rates during the respective periods. Translation adjustments resulting from the fluctuations in exchange rates are recorded as a separate component of accumulated other comprehensive loss in stockholders’ equity within the Condensed Consolidated Balance Sheets, while transaction gains and losses are recorded within the Condensed Consolidated Statements of Income. Deferred taxes are not recorded on cumulative foreign currency translation adjustments when the Company expects the foreign earnings to be permanently reinvested.

Significant Accounting Policies and Practices (Policies)

3 Months Ended

Mar. 31, 2023

The accompanying unaudited Condensed Consolidated Financial Statements of the Company have been prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”) for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, certain information and disclosures normally included in the financial statements have been condensed or omitted as permitted by such rules and regulations.

All adjustments (consisting only of adjustments of a normal and recurring nature) considered necessary for a fair presentation have been included. Operating results during the three months ended March 31, 2023 are not necessarily indicative of the results to be expected for any other interim period or the fiscal year ending December 31, 2023. The financial statements presented in this report should be read in conjunction with the Company’s annual Consolidated Financial Statements and notes thereto included in the Annual Report on Form 10-K for the year ended December 31, 2022 filed on February 24, 2023 with the Securities and Exchange Commission.

Principles of Consolidation

The unaudited Condensed Consolidated Financial Statements include the accounts of the Company, its wholly owned subsidiaries, and Variable Interest Entities ("VIEs") in which the Company is the primary beneficiary. The Company is the primary beneficiary of a VIE when the Company has the power to direct activities that most significantly affect the economic performance of the VIE. If the Company is not the primary beneficiary in a VIE, the Company accounts for the investment in the VIE in accordance with applicable U.S. GAAP. As of March 31, 2023 and December 31, 2022, assets related to consolidated VIEs were $54.4 million and $57.1 million, respectively, which were primarily related to right-of-use (“ROU”) assets and property and equipment, net. As of March 31, 2023 and December 31, 2022, liabilities related to consolidated VIEs were $49.7 million and $50.9 million, respectively, which were primarily related to operating and finance lease liabilities. All intercompany profits, transactions and balances have been eliminated in consolidation.

Cash and Cash Equivalents

Cash equivalents represent funds temporarily invested in money market instruments with maturities of three months or less. Cash equivalents are stated at cost, which approximates fair value. Cash and cash equivalents that are restricted as to withdrawal or use under the terms of certain contractual agreements were $0.7 million and $0.6 million as of March 31, 2023 and December 31, 2022, respectively, and were included in Cash and cash equivalents within the Condensed Consolidated Balance Sheets.

Allowance for Doubtful Accounts

Accounts receivable, net of the allowance for doubtful accounts, represents the Company’s estimate of the amount that ultimately will be realized in cash. The Company reviews the adequacy of its allowance for doubtful accounts on an ongoing basis, primarily using a review of specific accounts, as well as historical collection trends and aging of receivables, and records adjustments to the allowance as necessary. The Company’s allowance for doubtful accounts, which was included in Accounts receivable, net, within the Condensed Consolidated Balance Sheets, was $3.9 million and $4.0 million as of March 31, 2023 and December 31, 2022, respectively.

Property and Equipment, Net

Property and equipment includes the Company's equipment, internal-use software, vehicles, leasehold improvements and construction/development in process. Property and equipment are stated at cost, less accumulated depreciation and amortization, whenever applicable.

Certain costs incurred in the planning and evaluation stage of internal-use software projects are recorded to expense as incurred. Costs associated with directly obtaining, developing or upgrading internal-use software are capitalized and included as Software in Property and equipment, net, within the Condensed Consolidated Balance Sheets. When the internal-use software is ready for its intended use, it is amortized on a straight-line basis over the estimated useful life of the internal-use software, which is typically 3 years.

Equipment and vehicles are depreciated on a straight-line basis over the estimated useful lives ranging from 1 to 10 years. Expenditures for major renewals and improvements that extend the useful life of property and equipment are capitalized. Leasehold improvements are amortized on a straight-line basis over the terms of the respective leases or the useful lives of the improvements, whichever is shorter.

Equity Investments in Unconsolidated Entities

The Company has ownership interests in 34 active partnerships, joint ventures or similar arrangements that operate parking facilities, of which 28 are consolidated under the VIE or voting interest models and 6 are unconsolidated where the Company’s ownership interests range from 30-50 percent and for which there are no indicators of control. The Company accounts for such investments under the equity method of accounting, and the Company’s underlying share of each investee’s equity of $12.1 million and $11.9 million as of March 31, 2023 and December 31, 2022, respectively, was included in Other noncurrent assets within the Condensed Consolidated Balance Sheets. As the operations of these entities are consistent with the Company’s underlying core business operations, the equity in earnings of these investments were included in Services revenue - lease type contracts within the Condensed Consolidated Statements of Income. The equity earnings in these related investments were $0.7 million and $0.9 million during the three months ended March 31, 2023 and 2022, respectively.

Other Noncurrent Assets

Other noncurrent assets consisted of equity investments of unconsolidated entities, advances, deposits and cost of contracts, net, as of March 31, 2023 and December 31, 2022.

Accrued and Other Current Liabilities

Accrued and other current liabilities consisted of insurance, accrued rent, compensation, payroll withholdings, property, payroll and other taxes and other accrued expenses as of March 31, 2023 and December 31, 2022.

Noncontrolling Interests

Noncontrolling interests represent the noncontrolling holders’ percentage share of income (losses) from the subsidiaries in which the Company holds a controlling interest, but less than 100 percent, ownership interest. The results of these subsidiaries are consolidated and included within the Condensed Consolidated Financial Statements.

During the three months ended March 31, 2023, the Company recorded a $1.0 million liability related to its estimate of additional consideration (“contingent consideration") due to a former minority partner that formerly held a noncontrolling interest in a joint venture with the Company. The Company purchased the minority partner’s interest in the joint venture in 2020. The contingent consideration is contingent on the performance of the operations of the Bradley International Airport. The contingent consideration is not capped and, if any amount is due, would be payable to the former minority partner in April 2025. The $1.0 million was determined based on a probability weighting of potential payouts and recorded in Additional paid-in capital within the Condensed Consolidated Balance Sheets. In addition, the Company recorded a deferred tax asset of $0.3 million related to the contingent consideration during the three months ended March 31, 2023, which was recorded in Additional paid-in capital within the Condensed Consolidated Balance Sheets. The Company will continue to evaluate the criteria for making these payments in the future and adjust the liability when deemed necessary.

Additionally, during the three months ended March 31, 2023, the Company paid a former minority partner $2.1 million per the terms of an agreement between the Company and the former minority partner. The Company purchased the former minority partner’s entire noncontrolling interest in a joint venture with the Company as of December 31, 2022. Per the terms of the agreement, the Company will be required to make additional payments to the former minority partner over a ten-year period, amounting to a total of $4.5 million. The $2.1 million that was paid during the three months ended March 31, 2023 was included in Accrued and other current liabilities within the Condensed Consolidated Balance Sheets as of December 31, 2022.

Goodwill

Goodwill represents the excess of the purchase price paid over the fair value of net assets acquired. In accordance with the Financial Accounting Standards Board's ("FASB") authoritative accounting guidance on goodwill, the Company evaluates goodwill for impairment on an annual basis, or more often if events or circumstances change that could cause goodwill to become impaired. The Company has elected to assess the impairment of goodwill annually on October 1 or at an interim date if there is an event or change in circumstances indicating the carrying value may not be recoverable. The goodwill impairment test is performed at the reporting unit level; the Company's reporting units represent its operating segments, consisting of Commercial and Aviation. Factors that could trigger an impairment review include significant under-performance relative to expected historical or projected future operating results, significant changes in the use of acquired assets or the Company’s business strategy, and significant negative industry or economic trends.

The Company may perform a qualitative, rather than quantitative, assessment to determine whether it is more likely than not the fair value of a reporting unit is less than its carrying amount. If the Company determines impairment is present, the Company would need to perform a quantitative assessment. The determination of fair value of a reporting unit utilizes cash flow projections that assume certain future revenue and cost levels, comparable marketplace data, comparable company market valuations, assumed discount rates based upon current market conditions and other valuation factors, all of which involve the use of significant judgment

and estimates. The Company also assesses critical areas that may impact its business, including economic conditions, market related exposures, competition, changes in service offerings and changes in key personnel.

Other Intangible Assets, Net

Other Intangible Assets, net

Other intangible assets represent assets with finite lives that are amortized on a straight-line basis over their estimated useful lives. The Company evaluates other intangible assets on a periodic basis to determine whether events or circumstances warrant a revision to their remaining useful lives. In addition, other intangible assets are reviewed for impairment when circumstances change that would indicate the carrying value may not be recoverable. Assumptions and estimates about future values and remaining useful lives of intangible assets are complex and subjective, and can be affected by a variety of factors, including external factors such as industry and economic trends, and internal factors, such as changes in the Company's business strategy and forecasts. Although the Company believes the historical assumptions and estimates are reasonable and appropriate, different assumptions and estimates could materially impact reported financial results.

Long-Lived Assets

The Company evaluates long-lived assets, including ROU assets, leasehold improvements, equipment and construction/development in progress, for impairment whenever events or circumstances indicate that the carrying value of an asset or asset group may not be recoverable. The Company groups assets at the lowest level for which cash flows are separately identified in order to measure an impairment. Events or circumstances that would result in an impairment review include a significant change in the use of an asset, the planned sale or disposal of an asset, or a projection that demonstrates continuing losses associated with the use of a long-lived asset or asset group. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of the asset or asset group to future undiscounted cash flows expected to be generated by the asset or asset group. If the asset or asset group is determined to be impaired, the impairment recognized is measured by the amount by which the carrying value of the asset or asset group exceeds its fair value.

Assumptions and estimates used to determine cash flows in the evaluation of impairment and the fair values used to determine the impairment are subject to a degree of judgment and complexity. Any future changes to the assumptions and estimates resulting from changes in actual results or market conditions from those anticipated may affect the carrying value of long-lived assets or asset groups and could result in impairment charges. Future events that may result in impairment charges include economic volatility or other factors that could decrease revenues and profitability of existing locations and changes in the cost structure of existing facilities, such as increasing labor and benefit costs.

Foreign Operations

The Company has foreign operations in Canada, Puerto Rico, the United Kingdom and India. Assets and liabilities of the Company’s foreign operations are translated into U.S. dollars at the rate in effect on the respective balance sheet date, while income and expenses are translated at the average rates during the respective periods. Translation adjustments resulting from the fluctuations in exchange rates are recorded as a separate component of accumulated other comprehensive loss in stockholders’ equity within the Condensed Consolidated Balance Sheets, while transaction gains and losses are recorded within the Condensed Consolidated Statements of Income. Deferred taxes are not recorded on cumulative foreign currency translation adjustments when the Company expects the foreign earnings to be permanently reinvested.