BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	6 Months Ended
Jun. 30, 2019
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation: The accompanying unaudited Condensed Consolidated Financial Statements include the accounts of Stericycle, Inc. and its subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. The Company's Condensed Consolidated Financial Statements were prepared in accordance with U.S. GAAP and include the assets, liabilities, revenues and expenses of all wholly owned subsidiaries and majority-owned subsidiaries over which the Company exercises control. Outside shareholders' interests in subsidiaries are shown on the Condensed Consolidated Financial Statements as “Noncontrolling interests." The accompanying unaudited Condensed Consolidated Financial Statements as of June 30, 2019 and for the three and six months ended June 30, 2019 and 2018 have been prepared pursuant to the rules and regulations of the SEC for interim reporting and, therefore, do not include all information and footnote disclosures normally included in audited financial statements prepared in conformity with U.S. GAAP. However, in the opinion of management, all adjustments, consisting of normal recurring adjustments necessary to present fairly the results of operations, financial position and cash flows have been made. These Condensed Consolidated Financial Statements should be read in conjunction with the consolidated financial statements and notes thereto included in the 2018 Form 10-K. The results of operations for any interim period are not necessarily indicative of the results of operations to be expected for the full year or any other period.
Use of Estimates	Use of Estimates: The preparation of financial statements in conformity with U.S. GAAP requires the Company to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Some areas where the Company makes estimates include its allowance for doubtful accounts, credit memo reserve, accrued employee health and welfare benefits, environmental liabilities, stock-based compensation expense, income tax liabilities, accrued auto and workers’ compensation insurance claims, intangible asset valuations and long-lived asset and goodwill impairment assessments. Such estimates are based on historical trends and on various other assumptions that are believed to be reasonable under the circumstances. Actual results could differ from the Company’s estimates.
Leases	Leases (Accounted for as of January 1, 2019 and thereafter under ASC 842): Operating leases are included in Operating lease ROU assets, Operating lease liabilities and Long-term operating lease liabilities on the Company’s Condensed Consolidated Balance Sheets. Finance leases are included in Property, plant and equipment, Current portion of long-term debt, and Long-term debt on the Condensed Consolidated Balance Sheets. Operating lease ROU assets, Operating lease liabilities and Long-term operating lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at commencement date. Nearly all of the Company’s lease contracts do not provide a readily determinable implicit rate. For these contracts, the Company uses an estimated incremental borrowing rate, which is based on information available at the lease commencement. The Company used estimated incremental borrowing rates as of January 1, 2019 for operating leases that commenced prior to that date. The Company’s leases generally do not require material variable lease payments and generally do not contain options to purchase the leased property, any material residual value guarantees, or material restrictive covenants. At commencement, the Operating lease ROU asset is equal to the lease liability and is adjusted for lease incentives and initial direct costs incurred. The Company reviews all options to extend, terminate, or purchase its ROU assets at the commencement of the lease and on an ongoing basis and accounts for these options when they are reasonably certain of being exercised. Lease expense for minimum lease payments is recognized on a straight-line basis over the lease term. The Company has lease agreements with lease and non-lease components, including payments for common area maintenance and vehicle maintenance costs, which are accounted for separately for each class of underlying assets. In addition, the Company applies the short-term lease recognition exemption for leases with terms at commencement of not greater than 12 months.
New Accounting Standards	Adoption of New Accounting Standards: Leases In February 2016, the FASB issued ASC 842. The amended guidance, which was effective for the Company on January 1, 2019, requires the recognition of lease assets and lease liabilities on the balance sheet for those leases with terms in excess of 12 months and previously classified as operating leases. The Company elected the optional transition method which allows entities to continue to apply historical accounting guidance in the comparative periods presented. The Company elected to apply a package of practical expedients which allowed it to not reassess at transition: (i) whether any expired or existing contracts are or contain leases; (ii) lease classification for any expired or existing leases and (iii) whether initial direct costs for any expired or existing leases qualify for capitalization under the amended guidance. The standard had a material impact on the Company’s Condensed Consolidated Balance Sheets, but did not have an impact on the Company’s Condensed Consolidated Statements of (Loss) Income. The most significant impact was the recognition of ROU assets and lease liabilities for operating leases, while the Company’s accounting for finance leases remained substantially unchanged (see Note 5 – Leases). Derivatives and Hedging In August 2017, the FASB issued ASU No. 2017-12, “Derivatives and Hedging” (Topic 815): Targeted Improvements to Accounting for Hedging Activities (“ASU 2017-12”). ASU 2017-12 amends the hedge accounting recognition and presentation requirements with the objective of improving the financial reporting of hedging relationships to better portray the economic results of an entity’s risk management activities in its financial statements and enhance the transparency and understandability of hedge transactions. In addition, ASU 2017-12 makes improvements to simplify the application of the hedge accounting guidance. ASU 2017-12 was effective for the Company on January 1, 2019, and the adoption did not have a material impact on the Condensed Consolidated Financial Statements. Stranded Tax Effects In February 2018, the FASB issued ASU 2018-02, “Income Statement - Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income” (“ASU 2018-02”), which allows for stranded tax effects in accumulated other comprehensive income resulting from the Tax Act to be reclassified to retained earnings. ASU 2018-02 was effective for the Company on January 1, 2019. The adoption of ASU 2018-02 did not have a material impact on the Condensed Consolidated Financial Statements. Stock Compensation In June 2018, the FASB issued ASU 2018-07, “Compensation – Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting” (“ASU 2018-07”). ASU 2018-07 extends the scope of Topic 718 to include share-based payment transactions for acquiring goods and services from nonemployees. ASU 2018-07 was effective for the Company on January 1, 2019. The adoption of ASU 2018-07 did not have a material impact on the Condensed Consolidated Financial Statements. Changes in Stockholders Equity and Noncontrolling Interest In August 2018, the SEC issued the final rule amending Rule 3-04 of Regulation S-X (“Rule 3-04”), which requires entities to disclose changes in stockholders’ equity in the form of a reconciliation for the current and comparative year-to-date interim periods, with subtotals for each interim period. The Company adopted Rule 3-04 in the first quarter of fiscal 2019. Accounting Standards Issued But Not Yet Adopted Financial Instrument Credit Losses In June 2016, the FASB issued ASU No. 2016-13, “Financial Instruments – Credit Losses” (“ASU 2016-13”) associated with the measurement of credit losses on financial instruments. ASU 2016-13 replaces the current incurred loss impairment methodology of recognizing credit losses when a loss is probable, with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to assess credit loss estimates. The amended guidance is effective for us on January 1, 2020. The Company is evaluating the impact of adopting ASU 2016-13 on the Condensed Consolidated Financial Statements. Implementation Costs Incurred in a Cloud Computing Arrangement In August 2018, the FASB issued ASU 2018-15, “Intangibles - Goodwill and Other - Internal Use Software (Subtopic 250-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract” (“ASU 2018-15”). ASU 2018-15 aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs for internal-use software. The accounting for any hosting contract is unchanged. ASU 2018-15 is effective on January 1, 2020 with early adoption permitted, including adoption in any interim period. The Company is evaluating the impact of adopting ASU 2018-15 on the Condensed Consolidated Financial Statements.

BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)

6 Months Ended

Jun. 30, 2019

Basis of Presentation: The accompanying unaudited Condensed Consolidated Financial Statements include the accounts of Stericycle, Inc. and its subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. The Company's Condensed Consolidated Financial Statements were prepared in accordance with U.S. GAAP and include the assets, liabilities, revenues and expenses of all wholly owned subsidiaries and majority-owned subsidiaries over which the Company exercises control. Outside shareholders' interests in subsidiaries are shown on the Condensed Consolidated Financial Statements as “Noncontrolling interests."

The accompanying unaudited Condensed Consolidated Financial Statements as of June 30, 2019 and for the three and six months ended June 30, 2019 and 2018 have been prepared pursuant to the rules and regulations of the SEC for interim reporting and, therefore, do not include all information and footnote disclosures normally included in audited financial statements prepared in conformity with U.S. GAAP. However, in the opinion of management, all adjustments, consisting of normal recurring adjustments necessary to present fairly the results of operations, financial position and cash flows have been made. These Condensed Consolidated Financial Statements should be read in conjunction with the consolidated financial statements and notes thereto included in the 2018 Form 10-K. The results of operations for any interim period are not necessarily indicative of the results of operations to be expected for the full year or any other period.

Use of Estimates

Use of Estimates: The preparation of financial statements in conformity with U.S. GAAP requires the Company to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Some areas where the Company makes estimates include its allowance for doubtful accounts, credit memo reserve, accrued employee health and welfare benefits, environmental liabilities, stock-based compensation expense, income tax liabilities, accrued auto and workers’ compensation insurance claims, intangible asset valuations and long-lived asset and goodwill impairment assessments. Such estimates are based on historical trends and on various other assumptions that are believed to be reasonable under the circumstances. Actual results could differ from the Company’s estimates.

Leases

Leases (Accounted for as of January 1, 2019 and thereafter under ASC 842): Operating leases are included in Operating lease ROU assets, Operating lease liabilities and Long-term operating lease liabilities on the Company’s Condensed Consolidated Balance Sheets. Finance leases are included in Property, plant and equipment, Current portion of long-term debt, and Long-term debt on the Condensed Consolidated Balance Sheets.

Operating lease ROU assets, Operating lease liabilities and Long-term operating lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at commencement date. Nearly all of the Company’s lease contracts do not provide a readily determinable implicit rate. For these contracts, the Company uses an estimated incremental borrowing rate, which is based on information available at the lease commencement. The Company used estimated incremental borrowing rates as of January 1, 2019 for operating leases that commenced prior to that date.

The Company’s leases generally do not require material variable lease payments and generally do not contain options to purchase the leased property, any material residual value guarantees, or material restrictive covenants. At commencement, the Operating lease ROU asset is equal to the lease liability and is adjusted for lease incentives and initial direct costs incurred. The Company reviews all options to extend, terminate, or purchase its ROU assets at the commencement of the lease and on an ongoing basis and accounts for these options when they are reasonably certain of being exercised. Lease expense for minimum lease payments is recognized on a straight-line basis over the lease term.

The Company has lease agreements with lease and non-lease components, including payments for common area maintenance and vehicle maintenance costs, which are accounted for separately for each class of underlying assets.

In addition, the Company applies the short-term lease recognition exemption for leases with terms at commencement of not greater than 12 months.

New Accounting Standards

Adoption of New Accounting Standards:

Leases

In February 2016, the FASB issued ASC 842. The amended guidance, which was effective for the Company on January 1, 2019, requires the recognition of lease assets and lease liabilities on the balance sheet for those leases with terms in excess of 12 months and previously classified as operating leases. The Company elected the optional transition method which allows entities to continue to apply historical accounting guidance in the comparative periods presented.

The Company elected to apply a package of practical expedients which allowed it to not reassess at transition: (i) whether any expired or existing contracts are or contain leases; (ii) lease classification for any expired or existing leases and (iii) whether initial direct costs for any expired or existing leases qualify for capitalization under the amended guidance.

The standard had a material impact on the Company’s Condensed Consolidated Balance Sheets, but did not have an impact on the Company’s Condensed Consolidated Statements of (Loss) Income. The most significant impact was the recognition of ROU assets and lease liabilities for operating leases, while the Company’s accounting for finance leases remained substantially unchanged (see Note 5 – Leases).

Derivatives and Hedging

In August 2017, the FASB issued ASU No. 2017-12, “Derivatives and Hedging” (Topic 815): Targeted Improvements to Accounting for Hedging Activities (“ASU 2017-12”). ASU 2017-12 amends the hedge accounting recognition and presentation requirements with the objective of improving the financial reporting of hedging relationships to better portray the economic results of an entity’s risk management activities in its financial statements and enhance the transparency and understandability of hedge transactions. In addition, ASU 2017-12 makes improvements to simplify the application of the hedge accounting guidance. ASU 2017-12 was effective for the Company on January 1, 2019, and the adoption did not have a material impact on the Condensed Consolidated Financial Statements.

Stranded Tax Effects

In February 2018, the FASB issued ASU 2018-02, “Income Statement - Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income” (“ASU 2018-02”), which allows for stranded tax effects in accumulated other comprehensive income resulting from the Tax Act to be reclassified to retained earnings. ASU 2018-02 was effective for the Company on January 1, 2019. The adoption of ASU 2018-02 did not have a material impact on the Condensed Consolidated Financial Statements.

Stock Compensation

In June 2018, the FASB issued ASU 2018-07, “Compensation – Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting” (“ASU 2018-07”). ASU 2018-07 extends the scope of Topic 718 to include share-based payment transactions for acquiring goods and services from nonemployees. ASU 2018-07 was effective for the Company on January 1, 2019. The adoption of ASU 2018-07 did not have a material impact on the Condensed Consolidated Financial Statements.

Changes in Stockholders Equity and Noncontrolling Interest

In August 2018, the SEC issued the final rule amending Rule 3-04 of Regulation S-X (“Rule 3-04”), which requires entities to disclose changes in stockholders’ equity in the form of a reconciliation for the current and comparative year-to-date interim periods, with subtotals for each interim period. The Company adopted Rule 3-04 in the first quarter of fiscal 2019.

Accounting Standards Issued But Not Yet Adopted

Financial Instrument Credit Losses

In June 2016, the FASB issued ASU No. 2016-13, “Financial Instruments – Credit Losses” (“ASU 2016-13”) associated with the measurement of credit losses on financial instruments. ASU 2016-13 replaces the current incurred loss impairment methodology of recognizing credit losses when a loss is probable, with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to assess credit loss estimates. The amended guidance is effective for us on January 1, 2020. The Company is evaluating the impact of adopting ASU 2016-13 on the Condensed Consolidated Financial Statements.

Implementation Costs Incurred in a Cloud Computing Arrangement

In August 2018, the FASB issued ASU 2018-15, “Intangibles - Goodwill and Other - Internal Use Software (Subtopic 250-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract” (“ASU 2018-15”). ASU 2018-15 aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs for internal-use software. The accounting for any hosting contract is unchanged. ASU 2018-15 is effective on January 1, 2020 with early adoption permitted, including adoption in any interim period. The Company is evaluating the impact of adopting ASU 2018-15 on the Condensed Consolidated Financial Statements.