Summary of Significant Accounting Policies (Policies)	3 Months Ended
Mar. 31, 2019
Accounting Policies [Abstract]
Basis of Presentation, Policy	The condensed consolidated financial statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission. As a result, certain information and note disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States (U.S. GAAP) have been condensed or omitted. The Company believes that the disclosures made are adequate to make the information presented not misleading. The condensed consolidated financial statements reflect all adjustments, consisting of normal recurring items, which are, in the opinion of management, necessary to a fair statement of the results for the interim periods presented. These condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and related notes included in the Company's Form 10-K as filed with the Securities and Exchange Commission on February 22, 2019. All significant intercompany accounts and transactions have been eliminated in consolidation. All dollar amounts in the notes are presented in thousands except for per share data or unless otherwise specified.
Revenue Recognition, Policy	The Company derives its revenues by entering into agreements that are generally comprised of a single performance obligation, which is that freight is shipped for and received by the customer. The Company's three principal services are the revenue categories presented in the consolidated statements of earnings: 1) airfreight services, 2) ocean freight and ocean services, and 3) customs brokerage and other services. The Company typically satisfies its performance obligations as services are rendered over time. A typical shipment would include services rendered at origin, such as pick-up and delivery to port, freight services from origin to destination port and destination services, such as customs clearance and final delivery. The Company measures the performance of its obligations as services are completed over the life of a shipment, including services at origin, freight and destination. The Company fulfills nearly all of its performance obligations within a one to two month-period and contracts with customers have an original expected duration of less than one year. The Company satisfied nearly all performance obligations for the contract liabilities recorded as of December 31, 2018.
Leases, Policy	Effective January 1, 2019, the Company adopted new lease accounting guidance using a modified retrospective approach and recognizing a right-of-use (ROU) asset and lease liability on the balance sheet. On January 1, 2019, ROU assets and lease liabilities were recorded for all existing leases exceeding one-year terms and were measured at the present value of lease payments over the remaining lease term. The adoption of this accounting standard resulted in recording ROU assets and lease liabilities for operating leases of $343 million and $340 million, respectively, as of January 1, 2019. The adoption of this standard had no impact on retained earnings on the condensed consolidated balance sheet. In recording the ROU asset and lease liability, the Company elected to apply the following practical expedients: •Package of practical expedients not to reassess: ◦Whether a contract is or contains a lease, ◦Historical lease classification, and ◦Initial direct costs. •Use of hindsight when determining the lease term. Additionally, the Company has elected to apply the short-term lease exemption for leases with a non-cancelable period of twelve months or less and chose not to separate nonlease components from lease components and instead to account for each as a single lease component. The Company determines if an arrangement is a lease at inception. ROU assets represent the Company's right to use an underlying asset for the lease term, and lease liabilities represent the Company's obligation to make lease payments arising from the lease. All ROU assets and lease liabilities are recognized at the commencement date at the present value of lease payments over the lease term. ROU assets are adjusted for lease incentives and initial direct costs. The lease term includes renewal options exercisable at the Company's sole discretion when the Company is reasonably certain to exercise that option. As most of the Company's leases do not have an implicit rate, the Company uses an incremental borrowing rate based on market information available at the commencement date to determine the present value. Certain of our leases include variable payments, which may vary based upon changes in facts or circumstances after the start of the lease. We exclude variable payments from lease ROU assets and lease liabilities, to the extent not considered fixed, and instead expense variable payments as incurred. Lease expense is recognized on a straight-line basis over the lease term and is included in rent and occupancy expenses on the condensed consolidated statement of earnings.
Accounts Receivable, Policy	The Company maintains an allowance for doubtful accounts, which is reviewed at least monthly for estimated losses resulting from the inability of its customers to make required payments for services and advances. Additional allowances may be necessary in the future if the ability of customers to pay deteriorates. The Company has recorded an allowance for doubtful accounts in the amounts of $12,727 as of March 31, 2019 and $15,345 as of December 31, 2018. Additions and write-offs have not been significant in the periods presented.
Use of Estimates, Policy	The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of the assets and liabilities and disclosures of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the period. The Company uses estimates primarily in the following areas: accounts receivable valuation, accrual of costs related to ancillary services the Company provides, accrual of liabilities for the portion of the related exposure that the Company has self-insured, accrual of various tax liabilities including estimates associated with the U.S. enacted Tax Cuts and Jobs Act (the 2017 Tax Act), accrual of loss contingencies, calculation of share-based compensation expense and estimates related to determining the lease term when measuring ROU assets and lease liabilities. Actual results could be materially different from the estimated provisions and accruals recorded.
New Accounting Pronouncements, Policy	In June 2016, the Financial Accounting Standards Board (FASB) issued an Accounting Standards Update (ASU), which amends existing guidance for the accounting of credit losses on financial instruments. Under the ASU, the Company will record a valuation allowance for credit losses that are expected to be incurred over the financial asset’s contractual term. This standard will be effective for the Company on January 1, 2020 and is not expected to have a material effect on the consolidated financial statements as the new credit loss model will primarily apply to the Company's accounts receivable, which are of short duration and for which the Company has not historically experienced significant credit losses. However, the Company is still evaluating the impact of the new prescribed model compared to its current methodology.
Stock Plans, Policy	The Company recognizes stock compensation expense based on the fair value of awards granted to employees and directors under the Company’s omnibus incentive, stock option, director restricted stock and employee stock purchase rights plans. This expense, adjusted for expected forfeitures, is recognized in net earnings on a straight-line basis over the service periods as salaries and related costs. Restricted stock unit awards to certain employees meeting specific retirement eligibility criteria at the time of grant are expensed immediately as there is no substantive service period associated with those awards.
Income Taxes, Policy	In December 2017, the 2017 Tax Act was enacted in the United States. Beginning January 1, 2018, foreign earnings of the Company's international subsidiaries are generally exempt from U.S. Federal income tax upon repatriation. Notwithstanding these changes, certain non-U.S. withholding taxes and foreign exchange gains and losses will continue to be applicable upon the repatriation of foreign earnings. During 2018 and 2019, the Internal Revenue Service (IRS) and the U.S. Department of Treasury (Treasury) issued additional guidelines and clarifying regulations related to the implementation of the 2017 Tax Act. The Company expects that additional guidance will continue to be issued in future periods. As this guidance is issued, the Company will continue to evaluate the information to determine whether any additional adjustments to its tax provisions are required. The 2017 Tax Act included provisions for Global Intangible Low-Taxed Income (GILTI) under which taxes on foreign income are imposed on the excess of a deemed return on tangible assets of certain foreign subsidiaries and for Base Erosion and Anti-Abuse Tax (BEAT) under which taxes are imposed on certain base eroding payments to affiliated foreign companies. The Company treats BEAT and GILTI as components of current income tax expense. Income tax expense for the three-month periods ended March 31, 2019 and 2018 had no tax expense related to GILTI or BEAT. In February 2018, the FASB issued amended guidance for reporting comprehensive income to reflect changes resulting from the 2017 Tax Act. The amendment, which had an effective date of January 1, 2019, provided the option to reclassify stranded tax effects resulting from the 2017 Tax Act within accumulated other comprehensive income (AOCI) to retained earnings. The Company elected to not reclassify stranded income tax effects from AOCI to retained earnings, including those related to implementation of the 2017 Tax Act.
Earnings Per Share, Policy	Diluted earnings attributable to shareholders per share is computed using the weighted average number of common shares and dilutive potential common shares outstanding. Dilutive potential shares represent outstanding stock options, including purchase options under the Company's employee stock purchase plan, and unvested restricted stock units. Basic earnings attributable to shareholders per share is calculated using the weighted average number of common shares outstanding without taking into consideration dilutive potential common shares outstanding.
Cash Equivalents, Policy	All highly liquid investments with a maturity of three months or less at date of purchase are considered to be cash equivalents.
Segment Reporting, Policy	The Company is organized functionally in geographic operating segments. Accordingly, management focuses its attention on revenues, net revenues¹, operating income, identifiable assets, capital expenditures, depreciation and amortization and equity generated in each of these geographical areas when evaluating the effectiveness of geographic management. Transactions among the Company’s various offices are conducted using the same arms-length pricing methodologies the Company uses when its offices transact business with independent agents. Certain costs are allocated among the segments based on the relative value of the underlying services, which can include allocation based on actual costs incurred or estimated cost plus a profit margin.

Summary of Significant Accounting Policies (Policies)

3 Months Ended

Mar. 31, 2019

The condensed consolidated financial statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission. As a result, certain information and note disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States (U.S. GAAP) have been condensed or omitted. The Company believes that the disclosures made are adequate to make the information presented not misleading. The condensed consolidated financial statements reflect all adjustments, consisting of normal recurring items, which are, in the opinion of management, necessary to a fair statement of the results for the interim periods presented. These condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and related notes included in the Company's Form 10-K as filed with the Securities and Exchange Commission on February 22, 2019.

All significant intercompany accounts and transactions have been eliminated in consolidation. All dollar amounts in the notes are presented in thousands except for per share data or unless otherwise specified.

Revenue Recognition, Policy

The Company derives its revenues by entering into agreements that are generally comprised of a single performance obligation, which is that freight is shipped for and received by the customer. The Company's three principal services are the revenue categories presented in the consolidated statements of earnings: 1) airfreight services, 2) ocean freight and ocean services, and 3) customs brokerage and other services.

The Company typically satisfies its performance obligations as services are rendered over time. A typical shipment would include services rendered at origin, such as pick-up and delivery to port, freight services from origin to destination port and destination services, such as customs clearance and final delivery. The Company measures the performance of its obligations as services are completed over the life of a shipment, including services at origin, freight and destination. The Company fulfills nearly all of its performance obligations within a one to two month-period and contracts with customers have an original expected duration of less than one year. The Company satisfied nearly all performance obligations for the contract liabilities recorded as of December 31, 2018.

Leases, Policy

Effective January 1, 2019, the Company adopted new lease accounting guidance using a modified retrospective approach and recognizing a right-of-use (ROU) asset and lease liability on the balance sheet. On January 1, 2019, ROU assets and lease liabilities were recorded for all existing leases exceeding one-year terms and were measured at the present value of lease payments over the remaining lease term. The adoption of this accounting standard resulted in recording ROU assets and lease liabilities for operating leases of $343 million and $340 million, respectively, as of January 1, 2019. The adoption of this standard had no impact on retained earnings on the condensed consolidated balance sheet.

In recording the ROU asset and lease liability, the Company elected to apply the following practical expedients:

•Package of practical expedients not to reassess:

◦Whether a contract is or contains a lease,

◦Historical lease classification, and

◦Initial direct costs.

•Use of hindsight when determining the lease term.

Additionally, the Company has elected to apply the short-term lease exemption for leases with a non-cancelable period of twelve months or less and chose not to separate nonlease components from lease components and instead to account for each as a single lease component.

The Company determines if an arrangement is a lease at inception. ROU assets represent the Company's right to use an underlying asset for the lease term, and lease liabilities represent the Company's obligation to make lease payments arising from the lease. All ROU assets and lease liabilities are recognized at the commencement date at the present value of lease payments over the lease term. ROU assets are adjusted for lease incentives and initial direct costs. The lease term includes renewal options exercisable at the Company's sole discretion when the Company is reasonably certain to exercise that option. As most of the Company's leases do not have an implicit rate, the Company uses an incremental borrowing rate based on market information available at the commencement date to determine the present value. Certain of our leases include variable payments, which may vary based upon changes in facts or circumstances after the start of the lease. We exclude variable payments from lease ROU assets and lease liabilities, to the extent not considered fixed, and instead expense variable payments as incurred. Lease expense is recognized on a straight-line basis over the lease term and is included in rent and occupancy expenses on the condensed consolidated statement of earnings.

Accounts Receivable, Policy

The Company maintains an allowance for doubtful accounts, which is reviewed at least monthly for estimated losses resulting from the inability of its customers to make required payments for services and advances. Additional allowances may be necessary in the future if the ability of customers to pay deteriorates. The Company has recorded an allowance for doubtful accounts in the amounts of $12,727 as of March 31, 2019 and $15,345 as of December 31, 2018. Additions and write-offs have not been significant in the periods presented.

Use of Estimates, Policy

The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of the assets and liabilities and disclosures of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the period. The Company uses estimates primarily in the following areas: accounts receivable valuation, accrual of costs related to ancillary services the Company provides, accrual of liabilities for the portion of the related exposure that the Company has self-insured, accrual of various tax liabilities including estimates associated with the U.S. enacted Tax Cuts and Jobs Act (the 2017 Tax Act), accrual of loss contingencies, calculation of share-based compensation expense and estimates related to determining the lease term when measuring ROU assets and lease liabilities. Actual results could be materially different from the estimated provisions and accruals recorded.

New Accounting Pronouncements, Policy

In June 2016, the Financial Accounting Standards Board (FASB) issued an Accounting Standards Update (ASU), which amends existing guidance for the accounting of credit losses on financial instruments. Under the ASU, the Company will record a valuation allowance for credit losses that are expected to be incurred over the financial asset’s contractual term. This standard will be effective for the Company on January 1, 2020 and is not expected to have a material effect on the consolidated financial statements as the new credit loss model will primarily apply to the Company's accounts receivable, which are of short duration and for which the Company has not historically experienced significant credit losses. However, the Company is still evaluating the impact of the new prescribed model compared to its current methodology.

Stock Plans, Policy

The Company recognizes stock compensation expense based on the fair value of awards granted to employees and directors under the Company’s omnibus incentive, stock option, director restricted stock and employee stock purchase rights plans. This expense, adjusted for expected forfeitures, is recognized in net earnings on a straight-line basis over the service periods as salaries and related costs. Restricted stock unit awards to certain employees meeting specific retirement eligibility criteria at the time of grant are expensed immediately as there is no substantive service period associated with those awards.

Income Taxes, Policy

In December 2017, the 2017 Tax Act was enacted in the United States. Beginning January 1, 2018, foreign earnings of the Company's international subsidiaries are generally exempt from U.S. Federal income tax upon repatriation. Notwithstanding these changes, certain non-U.S. withholding taxes and foreign exchange gains and losses will continue to be applicable upon the repatriation of foreign earnings.

During 2018 and 2019, the Internal Revenue Service (IRS) and the U.S. Department of Treasury (Treasury) issued additional guidelines and clarifying regulations related to the implementation of the 2017 Tax Act. The Company expects that additional guidance will continue to be issued in future periods. As this guidance is issued, the Company will continue to evaluate the information to determine whether any additional adjustments to its tax provisions are required.

The 2017 Tax Act included provisions for Global Intangible Low-Taxed Income (GILTI) under which taxes on foreign income are imposed on the excess of a deemed return on tangible assets of certain foreign subsidiaries and for Base Erosion and Anti-Abuse Tax (BEAT) under which taxes are imposed on certain base eroding payments to affiliated foreign companies. The Company treats BEAT and GILTI as components of current income tax expense. Income tax expense for the three-month periods ended March 31, 2019 and 2018 had no tax expense related to GILTI or BEAT.

In February 2018, the FASB issued amended guidance for reporting comprehensive income to reflect changes resulting from the 2017 Tax Act. The amendment, which had an effective date of January 1, 2019, provided the option to reclassify stranded tax effects resulting from the 2017 Tax Act within accumulated other comprehensive income (AOCI) to retained earnings. The Company elected to not reclassify stranded income tax effects from AOCI to retained earnings, including those related to implementation of the 2017 Tax Act.

Earnings Per Share, Policy

Diluted earnings attributable to shareholders per share is computed using the weighted average number of common shares and dilutive potential common shares outstanding. Dilutive potential shares represent outstanding stock options, including purchase options under the Company's employee stock purchase plan, and unvested restricted stock units. Basic earnings attributable to shareholders per share is calculated using the weighted average number of common shares outstanding without taking into consideration dilutive potential common shares outstanding.

Cash Equivalents, Policy

All highly liquid investments with a maturity of three months or less at date of purchase are considered to be cash equivalents.

Segment Reporting, Policy

The Company is organized functionally in geographic operating segments. Accordingly, management focuses its attention on revenues, net revenues¹, operating income, identifiable assets, capital expenditures, depreciation and amortization and equity generated in each of these geographical areas when evaluating the effectiveness of geographic management. Transactions among the Company’s various offices are conducted using the same arms-length pricing methodologies the Company uses when its offices transact business with independent agents. Certain costs are allocated among the segments based on the relative value of the underlying services, which can include allocation based on actual costs incurred or estimated cost plus a profit margin.