Waste Connections (WCN) 10-Q 30 Oct 18 2018 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2018	Oct. 22, 2018
Document Documentand Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Entity Registrant Name	WASTE CONNECTIONS, INC.
Entity Central Index Key	1,318,220
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		263,506,880

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Current assets:
Cash and equivalents	$ 244,389	$ 433,815
Accounts receivable, net of allowance for doubtful accounts of $15,305 and $17,154 at September 30, 2018 and December 31, 2017, respectively	625,048	554,458
Current assets held for sale	794	1,596
Prepaid expenses and other current assets	152,827	186,999
Total current assets	1,023,058	1,176,868
Restricted cash	83,399	122,652
Restricted investments	44,217	44,360
Property and equipment, net	5,069,767	4,820,934
Goodwill	4,813,296	4,681,774
Intangible assets, net	1,069,064	1,087,436
Long-term assets held for sale	745	12,625
Other assets, net	88,520	68,032
Total assets	12,192,066	12,014,681
Current liabilities:
Accounts payable	331,535	330,523
Book overdraft	19,087	19,223
Accrued liabilities	287,369	278,039
Deferred revenue	162,965	145,197
Current portion of contingent consideration	11,612	15,803
Current liabilities held for sale	928	2,155
Current portion of long-term debt and notes payable	1,753	11,659
Total current liabilities	815,249	802,599
Long-term debt and notes payable	3,747,209	3,899,572
Long-term portion of contingent consideration	43,412	31,482
Other long-term liabilities	339,817	316,191
Deferred income taxes	741,300	690,767
Total liabilities	5,686,987	5,740,611
Commitments and contingencies (Note 18)
Equity:
Common shares: 263,506,592 shares issued and 263,372,910 shares outstanding at September 30, 2018; 263,660,803 shares issued and 263,494,670 shares outstanding at December 31, 2017	4,147,909	4,187,568
Additional paid-in capital	124,317	115,743
Accumulated other comprehensive income	53,203	108,413
Treasury shares: 133,682 and 166,133 shares at September 30, 2018 and December 31, 2017, respectively
Retained earnings	2,174,135	1,856,946
Total Waste Connections' equity	6,499,564	6,268,670
Noncontrolling interest in subsidiaries	5,515	5,400
Total equity	6,505,079	6,274,070
Total liabilities and shareholders' equity	$ 12,192,066	$ 12,014,681

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Statement Of Financial Position [Abstract]
Allowance for doubtful accounts	$ 15,305	$ 17,154
Common stock, shares issued	263,506,592	263,660,803
Common stock, shares outstanding	263,372,910	263,494,670
Treasury shares	133,682	166,133

Condensed Consolidated Statemen

Condensed Consolidated Statements of Net Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Statement [Abstract]
Revenues	$ 1,281,110	$ 1,206,478	$ 3,661,209	$ 3,473,313
Operating expenses:
Cost of operations	736,122	695,122	2,120,947	2,024,402
Selling, general and administrative	139,014	128,200	398,582	383,600
Depreciation	148,232	136,941	423,866	395,008
Amortization of intangibles	26,871	26,613	79,444	76,886
Impairments and other operating items	(1,998)	832	6,106	141,333
Operating income	232,869	218,770	632,264	452,084
Interest expense	(32,078)	(32,471)	(96,874)	(92,763)
Interest income	1,467	1,656	3,677	3,131
Other income, net	732	1,709	2,376	3,561
Foreign currency transaction gain (loss)	(132)	(1,864)	(323)	(3,502)
Income before income tax provision	202,858	187,800	541,120	362,511
Income tax provision	(52,092)	(64,390)	(126,509)	(100,220)
Net income	150,766	123,410	414,611	262,291
Plus (Less): Net loss (income) attributable to noncontrolling interests	77	(183)	(218)	(559)
Net income attributable to Waste Connections	$ 150,843	$ 123,227	$ 414,393	$ 261,732
Earnings per common share attributable to Waste Connections' common stockholders:
Basic	$ 0.57	$ 0.47	$ 1.57	$ 0.99
Diluted	$ 0.57	$ 0.47	$ 1.57	$ 0.99
Shares used in the per share calculations:
Basic	263,628,838	263,443,064	263,657,274	263,298,839
Diluted	264,394,757	264,299,472	264,376,320	264,109,383
Cash dividends per common share	$ 0.14	$ 0.12	$ 0.42	$ 0.36

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Net income	$ 150,766	$ 123,410	$ 414,611	$ 262,291
Other comprehensive income (loss), before tax:
Foreign currency translation adjustment	35,455	84,500	(67,349)	155,153
Other comprehensive income (loss), before tax	39,082	90,698	(50,805)	158,903
Income tax expense related to items of other comprehensive income (loss)	(985)	(4,016)	(4,405)	(1,123)
Other comprehensive income (loss), net of tax	38,097	86,682	(55,210)	157,780
Comprehensive income	188,863	210,092	359,401	420,071
Plus (Less): Comprehensive loss (income) attributable to noncontrolling interests	77	(183)	(218)	(559)
Comprehensive income attributable to Waste Connections	188,940	209,909	359,183	419,512
Interest Rate Swap [Member]
Other comprehensive income (loss), before tax:
Amounts reclassified, gross	4,279	511	2,407	2,352
Changes in fair value, gross	863	2,181	15,828	305
Fuel [Member] | Commodity Contract [Member]
Other comprehensive income (loss), before tax:
Amounts reclassified, gross	(1,810)	789	(4,647)	2,765
Changes in fair value, gross	$ 295	$ 2,717	$ 2,956	$ (1,672)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Equity - USD ($) $ in Thousands	Common Stock [Member]Deferred Compensation Plan [Member]	Common Stock [Member]Performance Shares [Member]	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]	Retained Earnings [Member]	Noncontrolling Interests [Member]	Total
Beginning Balances at Dec. 31, 2016			$ 4,174,808	$ 102,220	$ (43,001)		$ 1,413,488	$ 7,362	$ 5,654,877
Beginning Balances, shares at Dec. 31, 2016			262,803,271
Beginning Balance, treasury shares at Dec. 31, 2016						337,397
Sale of common shares held in trust			$ 8,704						8,704
Sale of common shares held in trust, shares			140,344			(140,344)
Vesting of restricted share units (shares)	36,619	122,786	540,432
Tax withholdings related to net share settlements of equity-based compensation				(13,754)					(13,754)
Tax withholdings related to net share settlements of equity-based compensation, shares			(250,172)
Equity-based compensation				20,463					20,463
Exercise of stock options and warrants			$ 1,946						$ 1,946
Exercise of stock options and warrants, shares			49,954
Repurchase of common shares (shares)									0
Cash dividends on common shares							(95,201)		$ (95,201)
Amounts reclassified into earnings, net of taxes					3,433				3,433
Changes in fair value of cash flow hedges, net of taxes					(806)				(806)
Foreign currency translation adjustment					155,153				155,153
Acquisition of noncontrolling interest				698				(2,564)	(1,866)
Net income							261,732	559	262,291
Ending Balances at Sep. 30, 2017			$ 4,185,458	111,011	114,779		1,578,635	5,357	5,995,240
Ending Balances, shares at Sep. 30, 2017			263,443,234
Ending Balance, treasury shares at Sep. 30, 2017						197,053
Cumulative effect adjustment from adoption of new accounting pronouncement				1,384			(1,384)
Beginning Balances at Dec. 31, 2017			$ 4,187,568	115,743	108,413		1,856,946	5,400	$ 6,274,070
Beginning Balances, shares at Dec. 31, 2017			263,494,670						263,494,670
Beginning Balance, treasury shares at Dec. 31, 2017						166,133			166,133
Sale of common shares held in trust			$ 2,381						$ 2,381
Sale of common shares held in trust, shares			32,451			(32,451)
Vesting of restricted share units (shares)	5,069	154,181	480,577
Tax withholdings related to net share settlements of equity-based compensation				(14,976)					(14,976)
Tax withholdings related to net share settlements of equity-based compensation, shares			(217,135)
Equity-based compensation				23,550					$ 23,550
Exercise of stock options and warrants, shares			17,571
Repurchase of common shares (shares)			(594,474)						(594,474)
Repurchase of common shares			$ (42,040)						$ (42,040)
Cash dividends on common shares							(110,447)		(110,447)
Amounts reclassified into earnings, net of taxes					(1,721)				(1,721)
Changes in fair value of cash flow hedges, net of taxes					13,860				13,860
Foreign currency translation adjustment					(67,349)				(67,349)
Distributions to noncontrolling interests								(103)	(103)
Net income							414,393	218	414,611
Ending Balances at Sep. 30, 2018			$ 4,147,909	$ 124,317	$ 53,203		2,174,135	$ 5,515	$ 6,505,079
Ending Balances, shares at Sep. 30, 2018			263,372,910						263,372,910
Ending Balance, treasury shares at Sep. 30, 2018						133,682			133,682
Cumulative effect adjustment from adoption of new accounting pronouncement							$ 13,243		$ 13,243

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Cash flows from operating activities:
Net income	$ 414,611	$ 262,291
Adjustments to reconcile net income to net cash provided by operating activities:
Loss on disposal of assets and impairments	6,852	122,098
Depreciation	423,866	395,008
Amortization of intangibles	79,444	76,886
Foreign currency transaction loss	323	3,502
Deferred income taxes, net of acquisitions	45,765	(10,971)
Amortization of debt issuance costs	3,087	3,221
Share-based compensation	35,434	32,407
Interest income on restricted investments	(143)	(387)
Interest accretion	11,135	10,406
Adjustments to contingent consideration	349	17,754
Payment of contingent consideration recorded in earnings	(11)
Net change in operating assets and liabilities, net of acquisitions	17,080	(23,840)
Net cash provided by operating activities	1,037,792	888,375
Cash flows from investing activities:
Payments for acquisitions, net of cash acquired	(500,064)	(394,002)
Capital expenditures for property and equipment	(373,512)	(317,385)
Proceeds from disposal of assets	3,698	25,826
Change in restricted investments, net of interest income		1,920
Other	(568)	(3,465)
Net cash used in investing activities	(870,446)	(687,106)
Cash flows from financing activities:
Proceeds from long-term debt	165,737	896,947
Principal payments on notes payable and long-term debt	(387,700)	(666,724)
Payment of contingent consideration recorded at acquisition date	(5,459)	(5,840)
Change in book overdraft	(243)	13,814
Proceeds from option and warrant exercises		1,946
Payments for repurchase of common shares	(42,040)
Payments for cash dividends	(110,447)	(95,201)
Tax withholdings related to net share settlements of equity-based compensation	(14,976)	(13,754)
Debt issuance costs	(2,839)	(3,638)
Proceeds from sale of common shares held in trust	2,381	8,704
Other	(103)	(1,095)
Net cash provided by (used in) financing activities	(395,689)	135,159
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(528)	976
Net increase (decrease) in cash, cash equivalents and restricted cash	(228,871)	337,404
Cash, cash equivalents and restricted cash at beginning of period	556,467	169,112
Plus (less): change in cash held for sale	192	(27)
Cash, cash equivalents and restricted cash at end of period	327,788	506,489
Non-cash financing activities:
Liabilities assumed and notes payable issued to sellers of businesses acquired	$ 100,753	143,495
Non-cash consideration received for asset sales		$ 92,972

Basis of Presentation and Summa

Basis of Presentation and Summary	9 Months Ended
	Sep. 30, 2018
Basis of Presentation and Summary [Abstract]
Basis of Presentation and Summary	1. BASIS OF PRESENTATION AND SUMMARY The accompanying condensed consolidated financial statements relate to Waste Connections, Inc. and its subsidiaries (“WCI” or the “Company”) for the three and nine month periods ended September 30, 2018 and 2017. In the opinion of management, the accompanying balance sheets and related interim statements of net income, comprehensive income, cash flows and equity include all adjustments, consisting only of normal recurring items, necessary for their fair statement in conformity with U.S. generally accepted accounting principles (“GAAP”). Preparing financial statements requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses. Examples include accounting for landfills, self-insurance accruals, income taxes, allocation of acquisition purchase price, contingent consideration accruals and asset impairments. An additional area that involves estimation is when the Company estimates the amount of potential exposure it may have with respect to litigation, claims and assessments in accordance with the accounting guidance on contingencies. Actual results for all estimates could differ materially from the estimates and assumptions that the Company uses in the preparation of its condensed consolidated financial statements. Interim results are not necessarily indicative of results for a full year. These interim financial statements should be read in conjunction with the financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2017.

Reporting Currency

Reporting Currency	9 Months Ended
	Sep. 30, 2018
Reporting Currency [Abstract]
Reporting Currency	2. REPORTING CURRENCY The functional currency of the Company, as the parent corporate entity, and its operating subsidiaries in the United States, is the U.S. dollar. The functional currency of the Company’s Canadian operations is the Canadian dollar. The reporting currency of the Company is the U.S. dollar. The Company’s consolidated Canadian dollar financial position is translated to U.S. dollars by applying the foreign currency exchange rate in effect at the consolidated balance sheet date. The Company’s consolidated Canadian dollar results of operations and cash flows are translated to U.S. dollars by applying the average foreign currency exchange rate in effect during the reporting period. The resulting translation adjustments are included in other comprehensive income or loss. Gains and losses from foreign currency transactions are included in earnings for the period.

New Accounting Standards

New Accounting Standards	9 Months Ended
	Sep. 30, 2018
New Accounting Standards [Abstract]
New Accounting Standards	3. NEW ACCOUNTING STANDARDS Accounting Standards Adopted Revenue From Contracts With Customers . In May 2014, the Financial Accounting Standards Board (the “FASB”) issued guidance to provide a single, comprehensive revenue recognition model for all contracts with customers. The standard is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2017 for public entities. The Company adopted the amended guidance using the modified retrospective method as of January 1, 2018 for all ongoing customer contracts. The Company’s results of operations for the reported periods after January 1, 2018 are presented under this amended guidance, while prior period amounts are not adjusted and continue to be reported in accordance with historical accounting guidance. The impact of adopting the amended guidance primarily relates to the deferral of certain sales incentives, which previously were expensed as incurred, but under the new guidance are capitalized as Other assets and amortized to Selling, general and administrative expenses over the expected life of the customer relationship. The Company recognized a net increase to retained earnings of $13,243 as of January 1, 2018 for the cumulative impact of adopting the amended guidance. The cumulative impact was associated with both the capitalization of certain sales incentives as contract acquisition costs consisting of an asset in the amount of $16,296 and a related deferred tax liability of $4,058 and a change in accounting for revenue priced based on published indices at the Company’s Canada operations of $1,005 . Prior to adoption, the Company expensed approximately $16,000 in sales incentives annually. There were no other material impacts on the condensed consolidated financial statements as a result of the Company’s adoption of this amended guidance. For contracts with an effective term greater than one year, the Company applied the standard’s practical expedient that permits the exclusion of unsatisfied performance obligations as the Company’s right to consideration corresponds directly to the value provided to the customer for services completed to date and all future variable consideration is allocated to wholly unsatisfied performance obligations. The Company also applied the standard’s optional exemption for performance obligations related to contracts that have an original expected duration of one year or less. The Company applied the standard’s practical expedient that permits an entity to recognize the incremental costs of obtaining a contract as an expense when incurred if the amortization period of the asset that the entity would have recognized is one year or less. See Note 5 for additional information and disclosures related to this amended guidance. Classification of Certain Cash Receipts and Cash Payments . In August 2016, the FASB issued guidance that addresses eight targeted changes with respect to how cash receipts and cash payments are classified in the statements of cash flows, with the objective of reducing diversity in practice . The new standard is effective for public companies for financial statements issued for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. The guidance requires application using a retrospective transition method. The Company adopted this guidance as of January 1, 2018. The adoption of this guidance did not have a material impact on the Company’s statement of cash flows. Accounting for Income Taxes: Intra-Entity Asset Transfers of Assets Other than Inventory . In October 2016, the FASB issued guidance that eliminates the exception for all intra-entity sales of assets other than inventory. As a result, a reporting entity would recognize the tax expense from the sale of the asset in the seller’s tax jurisdiction when the transfer occurs, even though the pre-tax effects of that transaction are eliminated in consolidation. Any deferred tax asset that arises in the buyer’s jurisdiction would also be recognized at the time of the transfer. The modified retrospective approach will be required for transition to the new guidance, with a cumulative-effect adjustment recorded in retained earnings as of the beginning of the period of adoption. The new guidance is effective for public business entities in fiscal years beginning after December 15, 2017, including interim periods within those years. The Company adopted this guidance as of January 1, 2018. The adoption of this guidance did not have a material impact on the Company’s consolidated financial statements . Statement of Cash Flows: Restricted Cash . In November 2016, the FASB issued guidance that requires that the statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. Entities are also required to reconcile such total to amounts on the balance sheet and disclose the nature of the restrictions. The new standard is effective for public companies for financial statements issued for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. The Company adopted this guidance as of January 1, 2018. All prior periods have been adjusted to conform to the current period presentation, which resulted in an increase in cash used in investing activities of $39,494 and $3,544 for the nine months ended September 30, 2018 and 2017. Stock Compensation: Scope of Modification Accounting . In May 2017, the FASB issued guidance to clarify when to account for a change to the terms or conditions of a share-based payment award as a modification. Under the new guidance, modification accounting is required only if the fair value, the vesting conditions, or the classification of the award (as equity or liability) changes as a result of the change in terms or conditions. The new standard is effective prospectively for all companies for annual periods beginning on or after December 15, 2017. The Company adopted this guidance as of January 1, 2018. The adoption of this guidance did not have a material impact on the Company’s consolidated financial statements. Accounting for the Tax Effects of the Tax Cuts and Jobs Act . On December 22, 2017, the U.S. Securities and Exchange Commission staff issued Staff Accounting Bulletin No. 118 (“SAB 118”), which provides guidance on accounting for the tax effects of the Tax Cuts and Jobs Act (the “Tax Act”). SAB 118 provides a measurement period that should not extend beyond one year from the Tax Act enactment date for companies to complete the accounting under Accounting Standards Codification 740 (“ASC 740”) . In accordance with SAB 118, a company must reflect the income tax effects of those aspects of the Tax Act for which the accounting under ASC 740 is complete. To the extent that a company’s accounting for certain income tax effects of the Tax Act is incomplete but it is able to determine a reasonable estimate, it must record a provisional estimate in the financial statements. If a company cannot determine a provisional estimate to be included in the financial statements, it should continue to apply ASC 740 on the basis of the provisions of the tax laws that were in effect immediately before the enactment of the Tax Act. The Tax Act’s one-time deemed repatriation transition tax (the “Transition Tax”) on certain unrepatriated earnings of non-U.S. subsidiaries is a tax on previously untaxed accumulated and current earnings and profits of certain of the Company’s non-U.S. subsidiaries. To determine the amount of the Transition Tax, the Company must determine, in addition to other factors, the amount of post-1986 earnings and profits of the relevant subsidiaries, as well as the amount of non-U.S. income taxes paid on such earnings. In 2017, the Company was able to make a reasonable estimate of the Transition Tax and recorded a provisional Transition Tax obligation of $1,000 . During the three months ended September 30, 2018, the Company concluded its evaluation of the Transition Tax. However, the Company has not concluded on its policy regarding the accounting for the tax impacts of global intangible low-taxed income, and the permanently reinvested amounts attributable to the Company’s non-U.S. subsidiaries are considered provisional under SAB 118. Accounting Standards Pending Adoption Lease Accounting . In February 2016, the FASB issued guidance that requires lessees to recognize a right-of-use asset and a lease liability for virtually all of their leases (other than leases that meet the definition of a short-term lease). The liability will be equal to the present value of lease payments. The asset will be based on the liability, subject to adjustment, such as for initial direct costs. For income statement purposes, the FASB retained a dual model, requiring leases to be classified as either operating or finance. Operating leases will result in straight-line expense (similar to current operating leases) while finance leases will result in a front-loaded expense pattern (similar to current capital leases). Classification will be based on criteria that are largely similar to those applied in current lease accounting, but without explicit bright lines. The new standard is effective for public companies for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018, with early adoption permitted. The FASB issued new guidance in July 2018, which amends the guidance to allow the issuer to elect from two adoption alternatives: 1) apply the new guidance at the beginning of the earliest comparative period presented; or 2) apply the new guidance at the effective date and recognize a cumulative-effect adjustment, without adjusting the comparative periods presented. The Company plans to apply the new guidance at the effective date and recognize a cumulative effect adjustment. The Company is assessing the provisions of the lease accounting guidance and has acquired a software solution to manage and account for leases under the new standard. The Company continues to evaluate the impact of the guidance on its consolidated financial statements; however, the Company currently plans to apply the package of practical expedients to leases that commenced before the effective date whereby the Company will elect not to reassess the following: (1) whether any expired or existing contracts are or contain leases; (2) the lease classification for any expired or existing leases; and (3) whether initial direct costs exist for any existing leases. The Company is currently assessing the disclosure requirements under the new standard and it anticipates disclosing additional information, as necessary, to comply with the new standard. Derivatives and Hedging: Targeted Improvements to Accounting for Hedging Activities . In August 2017, the FASB issued guidance which improves the financial reporting of hedging relationships to better portray the economic results of an entity's risk management activities in its financial statements and make certain targeted improvements to simplify the application of the hedge accounting guidance in current GAAP. The amendments in this update are intended to better align an entity's risk management activities and financial reporting for hedging relationships through changes to both the designation and measurement guidance for qualifying hedging relationships and presentation of hedge results. The effective date for the standard is for fiscal years beginning after December 15, 2018. Early adoption is permitted. The Company does not expect the adoption of this guidance to have a material impact on its consolidated financial statements. SEC Simplified and Updated Disclosure Requirements . In August 2018, the U.S. Securities and Exchange Commission (the “SEC”) amended its rules to require an analysis of changes in stockholders’ equity in the financial statements included in Quarterly Reports on Form 10-Q. The analysis, which can be presented as a note or separate statement, is required for the current and comparative quarter and year-to-date interim periods. The amended rules will become effective 30 days after they are published in the Federal Register; however, the SEC’s Division of Corporation Finance issued a Compliance and Disclosure Interpretation (the “CDI”) that provides transition guidance related to this new disclosure. The CDI states that the amendments are effective for all filings made on or after the effective date; however, it also states that SEC staff would not object if a filer’s first presentation of the changes in stockholders’ equity was included in its Form 10-Q for the quarter that begins after the effective date of the amendments, which is the quarter ending March 31, 2019 for the Company. The Company will be including these additional disclosures beginning with its first quarter Form 10-Q in 2019.  

Reclassification

Reclassification	9 Months Ended
	Sep. 30, 2018
Reclassification [Abstract]
Reclassification	4. RECLASSIFICATION As disclosed within other footnotes of the financial statements, restricted cash and restricted investments reported in the Company’s prior year have been reclassified to conform with the 2018 presentation.

Revenue

Revenue	9 Months Ended
	Sep. 30, 2018
Revenue [Abstract]
Revenue	5. REVENUE The Company’s operations primarily consist of providing waste collection, transfer, disposal and recycling services, non-hazardous exploration and production (“E&P”) waste treatment, recovery and disposal services and intermodal services. The following table disaggregates the Company’s revenues by service line for the periods indicated:   Three months ended September 30, Nine months ended September 30,  2018 2017 2018 2017  Commercial $ 369,543 $ 342,961 $ 1,080,261 $ 1,005,110  Residential 300,026 286,068 881,927 845,493  Industrial and construction roll off 202,130 186,315 573,877 530,219  Total collection 871,699 815,344 2,536,065 2,380,822  Landfill 285,945 261,706 790,056 744,352  Transfer 187,961 155,058 495,317 445,612  Recycling 23,371 43,864 69,559 131,445  E&P 68,049 57,797 189,071 147,662  Intermodal and other 34,261 38,221 105,588 107,418  Intercompany (190,176) (165,512) (524,447) (483,998)  Total $ 1,281,110 $ 1,206,478 $ 3,661,209 $ 3,473,313   The factors that impact the timing and amount of revenue recognized for each service line may vary based on the nature of the service performed. Generally, the Company recognizes revenue at the time it performs a service. In the event that the Company bills for services in advance of performance, it recognizes deferred revenue for the amount billed and subsequently recognizes revenue at the time the service is provided. See Note 11 for additional information regarding revenue by reportable segment. Revenue by Service Line Solid Waste Collection The Company’s solid waste collection business involves the collection of waste for transport to transfer stations, or directly to landfills or recycling centers. Solid waste collection services include both recurring and temporary customer relationships. The standard customer service agreements generally range from one to three years in duration, although some exclusive franchises are for significantly longer periods. The fees received for collection services are based primarily on the market, collection frequency, type of service, type and volume or weight of the waste collected, the distance to the disposal facility and the cost of disposal. In general, residential collection fees are billed monthly or quarterly in advance. Substantially all of the deferred revenue recognized as of June 30, 2018 was recognized as revenue during the three months ended September 30, 2018 when the service was performed. Commercial customers are typically billed on a monthly basis based on the nature of the services provided during the period. Revenue recognized under these agreements is variable in nature based on the number of residential homes or businesses serviced during the period, the frequency of collection and the volume of waste collected. In addition, certain contracts have annual price escalation clauses that are tied to changes in an underlying base index such as a consumer price index which are unknown at contract inception. Solid waste collection revenue from sources other than customer contracts primarily relates to lease revenue associated with compactors. Revenue from these leasing arrangements was not material and represented an insignificant amount of total revenue for each of the reported periods. Landfill and Transfer Station Revenue at landfills is primarily generated by charging tipping fees to third parties based on the volume disposed and the nature of the waste. In general, fees are variable in nature and revenue is recognized at the time the waste is disposed at the facility. Revenue at transfer stations is primarily generated by charging tipping or disposal fees. The fees charged to third parties are based primarily on the market, type and volume or weight of the waste accepted, the distance to the disposal facility and the cost of disposal. In general, fees are billed and revenue is recognized at the time the service is performed. Revenue recognized under these agreements is variable in nature based on the volume of waste accepted at the transfer facility. Solid Waste Recycling Solid waste recycling revenues are generated by offering residential, commercial, industrial and municipal customers recycling services for a variety of recyclable materials, including compost, cardboard, office paper, plastic containers, glass bottles and ferrous and aluminum metals. The Company owns recycling operations and sells collected recyclable materials to third parties for processing before resale. In certain instances, the Company issues recycling rebates to municipal or commercial customers, which can be based on the price it receives upon the sale of recycled commodities, a fixed contractual rate or other measures. The Company also receives rebates when it disposes of recycled commodities at third-party facilities. The fees received are based primarily on the market, type and volume or weight of the materials sold. In general, fees are billed and revenue is recognized at the time title is transferred. Revenue recognized under these agreements is variable in nature based on the volume of materials sold. In addition, the amount of revenue recognized is based on commodity prices at the time of sale, which are unknown at contract inception. E&P Waste Treatment, Recovery and Disposal E&P revenue is primarily generated through the treatment, recovery and disposal of non-hazardous exploration and production waste from vertical and horizontal drilling, hydraulic fracturing, production and clean-up activity, as well as other services including closed loop collection systems and the sale of recovered products. E&P activity varies across market areas that are tied to the natural resource basins in which the drilling activity occurs and reflects the regulatory environment, pricing and disposal alternatives available in any given market. Revenue recognized under these agreements is variable in nature based on the volume of waste accepted or processed during the period. Intermodal and Other Intermodal revenue is primarily generated through providing intermodal services for the rail haul movement of cargo and solid waste containers in the Pacific Northwest through a network of intermodal facilities. The fees received for intermodal services are based on negotiated rates and vary depending on volume commitments by the shipper and destination. In general, fees are billed and revenue is recognized upon delivery. Revenue Recognition Service obligations of a long-term nature, e.g., solid waste collection service contracts, are satisfied over time, and revenue is recognized based on the value provided to the customer during the period. The amount billed to the customer is based on variable elements such as the number of residential homes or businesses for which collection services are provided, the volume of waste collected, transported and disposed, and the nature of the waste accepted. The Company does not disclose the value of unsatisfied performance obligations for these contracts as its right to consideration corresponds directly to the value provided to the customer for services completed to date and all future variable consideration is allocated to wholly unsatisfied performance obligations. Additionally, certain elements of long-term customer contracts are unknown upon entering into the contract, including the amount that will be billed in accordance with annual price escalation clauses, fuel recovery fee programs and commodity prices. The amount to be billed is often tied to changes in an underlying base index such as a consumer price index or a fuel or commodity index, and revenue is recognized once the index is established for the period. Accounts Receivable Accounts receivable are recorded when billed or accrued and represent claims against third parties that will be settled in cash. The carrying value of the Company’s receivables, net of the allowance for doubtful accounts, represents their estimated net realizable value. The Company estimates its allowance for doubtful accounts based on historical collection trends, type of customer such as municipal or non-municipal, the age of outstanding receivables and existing economic conditions. If events or changes in circumstances indicate that specific receivable balances may be impaired, further consideration is given to the collectability of those balances and the allowance is adjusted accordingly. Past-due receivable balances are written off when the Company’s internal collection efforts have been unsuccessful in collecting the amount due. Contract Acquisition Costs The incremental direct costs of obtaining a contract, which consist of sales incentives, are recognized as Other assets in the Company’s condensed consolidated balance sheet, and are amortized to Selling, general and administrative expense over the estimated life of the relevant customer relationship, which ranges from one to five years. The Company applied the standard’s practical expedient that permits an entity to recognize the incremental costs of obtaining a contract as an expense when incurred if the amortization period of the asset that the entity would have recognized is one year or less. As of September 30, 2018, the Company had $16,300 of deferred sales incentives. During the three and nine months ended September 30, 2018, the Company recorded amortization expense of $4,666 and $13,260 , respectively, for sales incentives costs . 

Landfill Accounting

Landfill Accounting	9 Months Ended
	Sep. 30, 2018
Landfill Accounting [Abstract]
Landfill Accounting	6. LANDFILL ACCOUNTING At September 30, 2018, the Company’s landfills consisted of 81 owned landfills, eight landfills operated under life-of-site operating agreements and four landfills operated under limited-term operating agreements. The Company’s landfills had site costs with a net book value of $2,868,628 at September 30, 2018. For the Company’s landfills operated under limited-term operating agreements and life-of-site operating agreements, the owner of the property (generally a municipality) usually owns the permit and the Company operates the landfill for a contracted term. Where the contracted term is not the life of the landfill, the property owner is generally responsible for final capping, closure and post-closure obligations. The Company is responsible for all final capping, closure and post-closure liabilities at the landfills it operates under life-of-site operating agreements. The Company’s internal and third-party engineers perform surveys at least annually to estimate the remaining disposal capacity at its landfills. Many of the Company’s existing landfills have the potential for expanded disposal capacity beyond the amount currently permitted. The Company’s landfill depletion rates are based on the remaining disposal capacity, considering both permitted and probable expansion airspace, at the landfills it owns and landfills it operates, but does not own, under life-of-site agreements. The Company’s landfill depletion rate is based on the term of the operating agreement at its operated landfill that has capitalized expenditures. Expansion airspace consists of additional disposal capacity being pursued through means of an expansion that has not yet been permitted. Expansion airspace that meets certain criteria is included in the estimate of total landfill airspace. Based on remaining permitted capacity as of September 30, 2018, and projected annual disposal volumes, the average remaining landfill life for the Company’s owned landfills and landfills operated under life-of-site operating agreements is estimated to be approximately 26 years. As of September 30, 2018, the Company is seeking to expand permitted capacity at 11 of its owned landfills and three landfills that it operates under life-of-site operating agreements, and considers the achievement of these expansions to be probable. Although the Company cannot be certain that all future expansions will be permitted as designed, the average remaining life, when considering remaining permitted capacity, probable expansion capacity and projected annual disposal volume, of the Company’s owned landfills and landfills operated under life-of-site operating agreements is approximately 30 years, with lives ranging from approximately 1 to 158 years. During the nine months ended September 30, 2018 and 2017, the Company expensed $153,010 and $147,071 , respectively, or an average of $4.58 and $4.55 per ton consumed, respectively, related to landfill depletion at owned landfills and landfills operated under life-of-site agreements. The Company reserves for estimated final capping, closure and post-closure maintenance obligations at the landfills it owns and landfills it operates under life-of-site operating agreements. The Company calculates the net present value of its final capping, closure and post-closure liabilities by estimating the total obligation in current dollars, inflating the obligation based upon the expected date of the expenditure and discounting the inflated total to its present value using a credit-adjusted risk-free rate. Any changes in expectations that result in an upward revision to the estimated undiscounted cash flows are treated as a new liability and are inflated and discounted at rates reflecting current market conditions. Any changes in expectations that result in a downward revision (or no revision) to the estimated undiscounted cash flows result in a liability that is inflated and discounted at rates reflecting the market conditions at the time the cash flows were originally estimated. This policy results in the Company’s final capping, closure and post-closure liabilities being recorded in “layers.” The Company’s discount rate assumption for purposes of computing 2018 and 2017 “layers” for final capping, closure and post-closure obligations was 4.75% for both years, which reflects the Company’s long-term credit adjusted risk free rate as of the end of both 2017 and 2016. The Company’s inflation rate assumption is 2.5% for the years ending December 31, 2018 and 2017. The resulting final capping, closure and post-closure obligations are recorded on the condensed consolidated balance sheet along with an offsetting addition to site costs which is amortized to depletion expense as the remaining landfill airspace is consumed. Interest is accreted on the recorded liability using the corresponding discount rate. During the nine months ended September 30, 2018 and 2017, the Company expensed $9,583 and $8,757 respectively, or an average of $0.29 and $0.27 per ton consumed, respectively, related to final capping, closure and post-closure accretion expense. The following is a reconciliation of the Company’s final capping, closure and post-closure liability balance from December 31, 2017 to September 30, 2018:   Final capping, closure and post-closure liability at December 31, 2017 $ 237,817  Adjustments to final capping, closure and post-closure liabilities (13,139)  Liabilities incurred 11,750  Accretion expense associated with landfill obligations 9,583  Closure payments (2,411)  Assumption of closure liabilities from acquisitions 4,408  Foreign currency translation adjustment (1,098)  Final capping, closure and post-closure liability at September 30, 2018 $ 246,910  Liabilities incurred of $11,750 for the nine months ended September 30, 2018, represent non-cash increases to final capping, closure and post-closure liabilities. The adjustment to final capping, closure and post-closure liabilities primarily consisted of decreases in estimated closure and post closure costs at several of the Company’s landfills, most notably its Chiquita Canyon landfill, and changes to engineering estimates related to proposed expansions as well as timing of closure events and total site capacity. These decreases were partially offset by increases in estimated post closure costs and adjustments to reduce the remaining lives at certain sites. The Company performs its annual review of its cost and capacity estimates in the first quarter of each year. At September 30, 2018 and December 31, 2017, $44,760 and $43,684 , respectively, of the Company’s restricted cash balance and $12,639 and $12,406 , respectively, of the Company’s restricted investments balance was for purposes of securing its performance of future final capping, closure and post-closure obligations. 

Acquisitions

Acquisitions	9 Months Ended
	Sep. 30, 2018
Acquisitions [Abstract]
Acquisitions	7. ACQUISITIONS The Company acquired 15 individually immaterial non-hazardous solid waste collection, recycling, transfer and disposal businesses during the nine months ended September 30, 2018. The purchase price for one of these acquisitions included contingent consideration of $11,593 , representing the fair value of up to $12,582 of amounts payable to the former owners based on the achievement of certain operating targets specified in the asset purchase agreement. The fair value of the contingent consideration was determined using probability assessments of the expected future cash flows over the three -year period in which the obligation is expected to be settled, and applying a discount rate of 2.7% . As of September 30, 2018, the obligation recognized at the purchase date has not materially changed. Any changes in the fair value of the contingent consideration subsequent to the acquisition date will be charged or credited to expense until the contingency is settled. The total acquisition-related costs incurred during the nine months ended September 30, 2018 for these acquisitions was $4,907 . These expenses are included in Selling, general and administrative expenses in the Company’s Condensed Consolidated Statements of Net Income. In January 2017, the Company acquired Groot Industries, Inc. (“Groot”). At the time of the acquisition, Groot was the largest privately-owned solid waste services company in Illinois with total annual revenue of approximately $200,000 . Groot serves approximately 300,000 customers primarily in northern Illinois from a network of seven collection operations, six transfer stations and one recycling facility. In addition to the acquisition of Groot, the Company acquired 11 individually immaterial non-hazardous solid waste collection businesses during the nine months ended September 30, 2017. The total acquisition-related costs incurred during the nine months ended September 30, 2017 for these acquisitions was $ 4,418 . These expenses are included in Selling, general and administrative expenses in the Company’s Condensed Consolidated Statements of Net Income. The results of operations of these acquired businesses have been included in the Company’s Condensed Consolidated Financial Statements from their respective acquisition dates. The Company expects these acquired businesses to contribute towards the achievement of the Company’s strategy to expand through acquisitions. Goodwill acquired is attributable to the synergies and ancillary growth opportunities expected to arise after the Company’s acquisition of these businesses. The following table summarizes the consideration transferred to acquire these businesses and the preliminary amounts of identifiable assets acquired and liabilities assumed at the acquisition dates for the acquisitions consummated in the nine months ended September 30, 2018 and 2017:   2018 Acquisitions 2017 Acquisitions Fair value of consideration transferred:  Cash $ 500,064 $ 394,002  Debt assumed 65,010 56,958  Notes issued to sellers - 13,460  Fair value of operations exchanged - 81,097  565,074 545,517  Recognized amounts of identifiable assets acquired and liabilities assumed associated with businesses acquired:  Accounts receivable 12,817 19,312  Prepaid expenses and other current assets 2,355 4,336  Property and equipment 346,275 167,065  Long-term franchise agreements and contracts 10,888 54,674  Customer lists 27,330 28,033  Indefinite-lived intangibles - 5,830  Other intangibles 31,183 27,261  Other assets 19 3,052  Accounts payable and accrued liabilities (3,982) (12,022)  Deferred revenue (4,169) (9,657)  Contingent consideration (11,669) (35)  Other long-term liabilities (15,532) (1,080)  Deferred income taxes (391) (50,283)  Total identifiable net assets 395,124 236,486  Goodwill $ 169,950 $ 309,031   Goodwill acquired during the nine months ended September 30, 2018 and 2017, totaling $169,559 and $ 51,518 , respectively, is expected to be deductible for tax purposes. The fair value of acquired working capital related to five individually immaterial acquisitions completed during the twelve months ended September 30, 2018, is provisional pending receipt of information from the acquirees to support the fair value of the assets acquired and liabilities assumed. Any adjustments recorded relating to finalizing the working capital for these five acquisitions are not expected to be material to the Company’s financial position. The gross amount of trade receivables due under contracts acquired during the nine months ended September 30, 2018, is $14,015 , of which $1,198 is expected to be uncollectible. The gross amount of trade receivables due under contracts acquired during the nine months ended September 30, 2017, is $20,025 , of which $713 is expected to be uncollectible. The Company did not acquire any other class of receivable as a result of the acquisitions of these businesses.  

Assets Held for Sale

Assets Held for Sale	9 Months Ended
	Sep. 30, 2018
Assets Held for Sale [Abstract]
Assets Held for Sale	8. ASSETS HELD FOR SALE As of September 30, 2018, assets classified as held for sale consisted of an operating market in the Company’s Southern segment. The assets held for sale have been recognized at the lower of cost or fair value less costs to sell, which resulted in recording an estimated loss on disposal of $4,466 to Impairments and other operating items in the Condensed Consolidated Statements of Net Income during the year ended December 31, 2017. The expected consideration may include cash and non-monetary assets. During the three months ended September 30, 2018, the Company’s Southern segment completed the sale of an operation in the Louisiana market for total cash consideration of $1,250 . The Company’s assets and liabilities held for sale as of September 30, 2018 and December 31, 2017, were comprised of the following:   September 30, 2018 December 31, 2017 Current assets held for sale:  Cash and equivalents $ - $ 192  Accounts receivable 735 1,185  Other current assets 59 219  $ 794 $ 1,596 Long-term assets held for sale:  Property and equipment $ 413 $ 12,623  Goodwill 332 2  $ 745 $ 12,625 Current liabilities held for sale:  Accounts payable $ 157 $ 804  Accrued liabilities 22 215  Deferred revenue 749 1,136  $ 928 $ 2,155 

Intangible Assets, Net

Intangible Assets, Net	9 Months Ended
	Sep. 30, 2018
Intangible Assets, Net [Abstract]
Intangible Assets, Net	9. INTANGIBLE ASSETS, NET Intangible assets, exclusive of goodwill, consisted of the following at September 30, 2018:   Gross Carrying Amount Accumulated Amortization Accumulated Impairment Loss Net Carrying Amount Finite-lived intangible assets:  Long-term franchise agreements and contracts $ 483,749 $ (150,691) $ - $ 333,058  Customer lists 429,801 (219,104) - 210,697  Permits and other 349,207 (46,120) - 303,087  1,262,757 (415,915) - 846,842  Indefinite-lived intangible assets:  Solid waste collection and transportation permits 158,591 - - 158,591  Material recycling facility permits 42,283 - - 42,283  E&P facility permits 59,855 - (38,507) 21,348  260,729 - (38,507) 222,222  Intangible assets, exclusive of goodwill $ 1,523,486 $ (415,915) $ (38,507) $ 1,069,064   The weighted-average amortization period of long-term franchise agreements and contracts acquired during the nine months ended September 30, 2018 was 16.3 years. The weighted-average amortization period of customer lists acquired during the nine months ended September 30, 2018 was 10.0 years. The weighted-average amortization period of finite-lived permits and other intangibles acquired during the nine months ended September 30, 2018 was 40.0 years. Intangible assets, exclusive of goodwill, consisted of the following at December 31, 2017:   Gross Carrying Amount Accumulated Amortization Accumulated Impairment Loss Net Carrying Amount Finite-lived intangible assets:  Long-term franchise agreements and contracts $ 481,293 $ (123,591) $ - $ 357,702  Customer lists 405,683 (180,440) - 225,243  Permits and other 317,984 (35,715) - 282,269  1,204,960 (339,746) - 865,214 Indefinite-lived intangible assets:  Solid waste collection and transportation permits 158,591 - - 158,591  Material recycling facility permits 42,283 - - 42,283  E&P facility permits 59,855 - (38,507) 21,348  260,729 - (38,507) 222,222  Intangible assets, exclusive of goodwill $ 1,465,689 $ (339,746) $ (38,507) $ 1,087,436   Estimated future amortization expense for the next five years relating to finite-lived intangible assets is as follows:   For the year ending December 31, 2018 $ 105,991  For the year ending December 31, 2019 $ 95,653  For the year ending December 31, 2020 $ 85,751  For the year ending December 31, 2021 $ 75,561  For the year ending December 31, 2022 $ 65,904 

Long-Term Debt

Long-Term Debt	9 Months Ended
	Sep. 30, 2018
Long-Term Debt [Abstract]
Long-Term Debt	10. LONG-TERM DEBT The following table presents the Company’s long-term debt as of September 30, 2018 and December 31, 2017:   September 30, 2018 December 31, 2017  Revolver under Credit Agreement, bearing interest at 2.93 % (a) $ 169,950 $ 192,101  Term loan under Credit Agreement, bearing interest at 3.34 % (a) 1,637,500 1,637,500  2018 Senior Notes - 50,000  2019 Senior Notes 175,000 175,000  2021 Senior Notes 100,000 100,000  New 2021 Senior Notes 150,000 150,000  2022 Senior Notes 125,000 125,000  2023 Senior Notes 200,000 200,000  2024 Senior Notes 150,000 150,000  2025 Senior Notes 375,000 375,000  2026 Senior Notes 400,000 400,000  2027 Senior Notes 250,000 250,000  Tax-exempt bond, bearing interest at 1.61 % (a) 15,930 95,430  Notes payable to sellers and other third parties, bearing interest ranging from 2.75 % to 24.81 % (a) 14,950 26,290  3,763,330 3,926,321  Less – current portion (1,753) (11,659)  Less – debt issuance costs (14,368) (15,090)  $ 3,747,209 $ 3,899,572 ____________________ (a) Interest rates represent the interest rates incurred at September 30, 2018 .  2016 Master Note Purchase Agreement On June 1, 2016 the Company entered into that certain Master Note Purchase Agreement (as supplemented by that certain First Supplement to the 2016 NPA dated as of February 13, 2017 (the “2016 First Supplement”) and as amended, restated, amended and restated, assumed, supplemented or modified from time to time, the “2016 NPA”) with certain accredited institutional investors. On April 20, 2017, pursuant to the 2016 NPA, and the 2016 First Supplement, the Company issued and sold to certain accredited institutional investors $400,000 aggregate principal amount of senior unsecured notes consisting of $150,000 aggregate principal amount, which will mature on April 20, 2024 with an annual interest rate of 3.24% (the “2024 Senior Notes”) and $250,000 aggregate principal amount, which will mature on April 20, 2027 with an annual interest rate of 3.49% (the “2027 Senior Notes” and collectively with the 2024 Senior Notes, the “2017A Senior Notes”) in a private placement. The 2017A Senior Notes bear interest at fixed rates with interest payable in arrears semi-annually on the first day of October and April beginning on October 1, 2017, and on the respective maturity dates, until the principal thereunder becomes due and payable. On March 21, 2018, the Company entered into that certain Amendment No. 1 to Master Note Purchase Agreement (the “2016 NPA First Amendment”), with each of the holders party thereto, which amended the 2016 NPA. The 2016 NPA First Amendment, among other things, provided for certain amendments to the 2016 NPA to facilitate (i) certain conforming changes to align certain provisions of the 2016 NPA, the Assumed 2008 NPA (as defined below) and the Credit Agreement (as defined below) and (ii) the release of all subsidiary guarantors in relation to obligations under the 2016 NPA and the 2016 Senior Notes (as defined below) (the “2016 Release”). Pursuant to the terms and conditions of the 2016 NPA, the Company has outstanding senior unsecured notes (the “2016 Senior Notes”) consisting of (i) $150,000 of 2.39% senior notes due June 1, 2021 (the “New 2021 Senior Notes”), (ii) $200,000 of 2.75% senior notes due June 1, 2023 (the “2023 Senior Notes”), (iii) $400,000 of 3.03% senior notes due June 1, 2026 (the “2026 Senior Notes”) and (iv) $400,000 of the 2017A Senior Notes. No new notes were issued by the Company in connection with the 2016 NPA First Amendment. Under the terms and conditions of the 2016 NPA, the Company is authorized to issue and sell notes in the aggregate principal amount of $1,500,000 , inclusive of the outstanding $1,150,000 aggregate principal amount of 2016 Senior Notes that have been issued and sold by the Company, provided that the purchasers of the 2016 Senior Notes shall not have any obligation to purchase any additional notes issued pursuant to the 2016 NPA.  The 2016 Senior Notes are unsecured obligations and rank pari passu with obligations under the Credit Agreement and the 2008 Senior Notes (defined below). Following the 2016 Release, there are currently no subsidiary guarantors in relation to the obligations under the 2016 NPA or the 2016 Senior Notes. The 2016 Senior Notes are subject to representations, warranties, covenants and events of default customary for a private placement of senior unsecured notes. Upon the occurrence of an event of default, payment of the 2016 Senior Notes may be accelerated by the holders of the 2016 Senior Notes. The 2016 Senior Notes may also be prepaid by the Company at par plus a make-whole amount determined by the amount of excess, if any, of the discounted value of the remaining scheduled payments with respect to the called principal of such 2016 Senior Notes minus the amount of such called principal, provided that the make whole shall in no event be less than zero. The discounted value is determined using market-based discount rates. In addition, the Company will be required to offer to prepay the 2016 Senior Notes upon certain changes in control. The 2016 NPA also contemplates certain offers of prepayments for specified tax reasons or certain noteholder sanctions events. 2008 Master Note Purchase Agreement  On June 1, 2016, pursuant to the terms of the Agreement and Plan of Merger dated as of January 18, 2016, Water Merger Sub LLC, a Delaware limited liability company and a wholly-owned subsidiary of Progressive Waste Solutions Ltd., merged with and into Waste Connections US, Inc. (f/k/a Waste Connections, Inc.), a Delaware corporation (“Old Waste Connections”) with Old Waste Connections continuing as the surviving corporation and an indirect wholly-owned subsidiary of Waste Connections, Inc. (f/k/a Progressive Waste Solutions Ltd.), a corporation organized under the laws of Ontario, Canada (the “Progressive Waste acquisition”). Prior to the closing of the Progressive Waste acquisition, Old Waste Connections, certain subsidiaries of Old Waste Connections (together with Old Waste Connections, the “Obligors”) and certain holders of the 2008 Senior Notes (defined below) entered into that certain Amendment No. 6 (the “Sixth Amendment”) to that certain Master Note Purchase Agreement, dated July 15, 2008 (the “2008 NPA”). Following the closing of the Progressive Waste acquisition, the Company entered into that certain Assumption and Exchange Agreement (as amended, restated, amended and restated, supplemented or modified from time to time, the “Assumption Agreement”) with Old Waste Connections, to and in favor of the holders of the notes issued from time to time under the 2008 NPA as amended by Amendment No. 1 to the 2008 NPA dated as of July 20, 2009, as supplemented by First Supplement to the 2008 NPA dated as of October 26, 2009, as amended by Amendment No. 2 to the 2008 NPA dated as of November 24, 2010, as supplemented by Second Supplement to the 2008 NPA dated as of April 1, 2011, as amended by Amendment No. 3 to the 2008 NPA dated as of October 12, 2011, as amended by Amendment No. 4 to the 2008 NPA dated as of August 9, 2013, as amended by Amendment No. 5 to the 2008 NPA dated as of February 20, 2015, as supplemented by Third Supplement to the 2008 NPA dated as of June 11, 2015 and as modified by the Assumption Agreement (the 2008 NPA, as so amended, restated, amended and restated, supplemented or otherwise modified from time to time “Assumed 2008 NPA”). The term “Progressive Waste” is used herein in the context of references to Progressive Waste Solutions Ltd. and its shareholders prior to the completion of the Progressive Waste acquisition on June 1, 2016. On March 21, 2018, the Company entered into that certain Amendment No. 7 to the Assumed 2008 NPA (the “2008 NPA Seventh Amendment”), with each of the holders party thereto, which amended the Assumed 2008 NPA. The 2008 NPA Seventh Amendment, among other things, provides certain amendments to the Assumed 2008 NPA to facilitate (i) certain conforming changes to align the provisions of the Assumed 2008 NPA, the 2016 NPA and the Credit Agreement and (ii) the release of all subsidiary guarantors in relation to obligations under the Assumed 2008 NPA and the 2008 Senior Notes (the “2008 Release”). Pursuant to the terms and conditions of the Assumed 2008 NPA, the Company has outstanding senior unsecured notes (the “2008 Senior Notes”) consisting of $175,000 of 5.25% senior notes due 2019 (the “2019 Senior Notes”), $100,000 of 4.64% senior notes due 2021 (the “2021 Senior Notes), $125,000 of 3.09% senior notes due 2022 (the “2022 Senior Notes”) and $375,000 of 3.41% senior notes due 2025 (the “2025 Senior Notes”). The Company redeemed at maturity its $50,000 of 4.00% senior notes due April 2018 (the “2018 Senior Notes”) on April 2, 2018 using borrowings under its Credit Agreement. Under the terms and conditions of the Assumed 2008 NPA, the Company is authorized to issue and sell notes in the aggregate principal amount of $1,250,000 , inclusive of the outstanding $775,000 aggregate principal amount of 2008 Senior Notes assumed by the Company on June 1, 2016, provided that the purchasers of the 2008 Senior Notes shall not have any obligation to purchase any additional notes issued pursuant to the Assumed 2008 NPA.  The 2008 Senior Notes are unsecured obligations and rank pari passu with obligations under the Credit Agreement and the 2016 Senior Notes. Following the 2008 Release, there are no subsidiary guarantors in relation to the Company’s obligations under the Assumed 2008 NPA or the 2008 Senior Notes.  The 2008 Senior Notes are subject to representations, warranties, covenants and events of default customary for a private placement of senior unsecured notes. Upon the occurrence of an event of default, payment of the 2008 Senior Notes may be accelerated by the holders of the 2008 Senior Notes. The 2008 Senior Notes may also be prepaid by the Company at par plus a make-whole amount determined by the amount of excess, if any, of the discounted value of the remaining scheduled payments with respect to the called principal of such 2008 Senior Notes minus the amount of such called principal, provided that the make whole shall in no event be less than zero. The discounted value is determined using market-based discount rates. In addition, the Company will be required to offer to prepay the 2008 Senior Notes upon certain changes in control; however, no such prepayment offer was accepted in connection with the Progressive Waste acquisition. The Assumed 2008 NPA also contemplates certain offers of prepayments for specified tax reasons or certain noteholder sanctions events. Credit Agreement Details of the Credit Agreement are as follows:    September 30, 2018 December 31, 2017 Revolver under Credit Agreement  Available $ 1,252,021 $ 1,149,813  Letters of credit outstanding $ 140,529 $ 220,586  Total amount drawn, as follows: $ 169,950 $ 192,101  Amount drawn – Canadian prime rate loan $ - $ 16,739  Interest rate applicable – Canadian prime rate loan - 3.45%  Amount drawn – Canadian bankers’ acceptance $ 169,950 $ 175,362  Interest rate applicable – Canadian bankers’ acceptance 2.93% 2.64%  Commitment – rate applicable 0.12% 0.15%  Term loan under Credit Agreement  Amount drawn – U.S. based LIBOR loan $ 1,637,500 $ 1,637,500  Interest rate applicable – U.S. based LIBOR loan 3.34% 2.77%  On June 1, 2016, the Company entered into that certain Revolving Credit and Term Loan Agreement with Bank of America, N.A., acting through its Canada Branch, as global agent, the swing line lender and letter of credit issuer, Bank of America, N.A., as the U.S. Agent and a letter of credit issuer, the lenders (the “Lenders”) and any other financial institutions from time to time party thereto. On March 21, 2018 the Revolving Credit and Term Loan Agreement was amended and restated in its entirety pursuant to an Amended and Restated Revolving Credit and Term Loan Agreement (as amended, restated, amended and restated, supplemented or otherwise modified from time to time, the “Credit Agreement”) entered into by the Company and the Lenders and any other financial institutions from time to time party thereto. Entry into the Credit Agreement, among other things, facilitated the release of each of the Company’s subsidiaries guaranteeing the obligations under the Revolving Credit and Term Loan Agreement. There are no subsidiary guarantors under the Credit Agreement. The Credit Agreement has a scheduled maturity date of March 21, 2023 . Pursuant to the terms and conditions of the Credit Agreement, the Lenders remain committed to providing a $3,200,000 credit facility to the Company, consisting of (i) revolving advances up to an aggregate principal amount of $1,562,500 at any one time outstanding, and (ii) a term loan in an aggregate principal amount of $1,637,500 , which term loan was fully drawn at closing of the Revolving Credit and Term Loan Agreement and remained and continued to be fully drawn at closing of the Credit Agreement. As part of the aggregate commitments under the revolving advances, the Credit Agreement provides for letters of credit to be issued at the request of the Company in an aggregate amount not to exceed $500,000 and for swing line loans to be issued at the request of the Company in an aggregate amount not to exceed the lesser of $75,000 and the aggregate commitments under the revolving advances. This swing line sublimit is part of, and not in addition to, the aggregate commitments under the revolving advances. Existing letters of credit in place under the Revolving Credit and Term Loan Agreement are continued and now deemed issued under and governed by the terms of the Credit Agreement. Subject to certain specified conditions and additional deliveries, the Company has the option to request increases in the aggregate commitments for revolving advances and one or more additional term loans, provided that (i) the aggregate principal amount of such requests does not exceed $500,000 and (ii) the aggregate principal amount of commitments and term loans under the credit facility does not exceed $3,700,000 .  Advances are available under the Credit Agreement in U.S. dollars and Canadian dollars. Interest accrues on the term loan at a LIBOR rate or a base rate, at the Company’s option, plus an applicable margin. Interest accrues on revolving advances, at the Company’s option, (i) at a LIBOR rate or a base rate for U.S. dollar borrowings, plus an applicable margin, and (ii) at the Canadian prime rate for Canadian dollar borrowings, plus an applicable margin. Canadian dollar borrowings are also available by way of bankers' acceptances or BA equivalent loans (“BA loans”), subject to the payment of a drawing fee. The fees for letters of credit in US dollars and Canadian dollars are also based on the applicable margin. The applicable margin used in connection with interest rates and fees is based on the Company’s Leverage Ratio (as defined below). The applicable margin for LIBOR rate loans, drawing fees for bankers' acceptance and BA loans and letter of credit fees ranges from 1.00% to 1.50% , and the applicable margin for base rate loans, Canadian prime rate loans and swing line loans ranges from 0.00% to 0.50% . The Company will also pay a fee based on its Leverage Ratio (as defined below) on the actual daily unused amount of the aggregate revolving commitments. The borrowings under the Credit Agreement are unsecured. The Credit Agreement contains customary representations, warranties, covenants and events of default, including, among others, a change of control event of default and limitations on the incurrence of indebtedness and liens, new lines of business, mergers, transactions with affiliates and burdensome agreements. During the continuance of an event of default, the Lenders may take a number of actions, including, among others, declaring the entire amount then outstanding under the Credit Agreement to be due and payable. The Credit Agreement includes a financial covenant limiting, as of the last day of each fiscal quarter, the ratio of (a) (i) Consolidated Total Funded Debt (as defined in the Credit Agreement) as of such date less (ii) the sum of cash and cash equivalents of the Company and its subsidiaries on a dollar-for-dollar basis as of such date in excess of $50,000 up to a maximum of $200,000 (such that the maximum amount of reduction pursuant to this calculation does not exceed $150,000 ) to (b) Consolidated EBITDA (as defined in the Credit Agreement), measured for the preceding 12 months (the “Leverage Ratio”), to not more than 3.50 to 1.00 (or 3.75 to 1.00 during material acquisition periods, subject to certain limitations). The Credit Agreement also includes a financial covenant requiring the ratio of Consolidated EBIT (as defined in the Credit Agreement) to Consolidated Total Interest Expense (as defined in the Credit Agreement), in each case, measured for the preceding 12 months, to be not less than 2.75 to 1.00 . Tax Exempt Bonds In February 2018, the Company gave notice to redeem its Pennsylvania Economic Development Corporation IRB Bond with a remaining principal balance of $35,000 . The Company paid in full the principal and accrued interest on this bond on April 2, 2018. In February 2018, the Company gave notice to redeem its Mission Economic Development Corporation IRB Bond with a remaining principal balance of $24,000 . The Company paid in full the principal and accrued interest on this bond on April 2, 2018. In July 2018, the Company gave notice to redeem its 2009 Seneca County Industrial Development Agency IRB Bond with a remaining principal balance of $5,000 . The Company paid in full the principal and accrued interest on this bond on September 4, 2018. The Company’s West Valley tax-exempt bond, with a principal amount of $15,500 , matured August 1, 2018. The Company paid in full the principal and accrued interest on this bond on August 1, 2018.   

Segment Reporting

Segment Reporting	9 Months Ended
	Sep. 30, 2018
Segment Reporting [Abstract]
Segment Reporting	11. SEGMENT REPORTING The Company’s revenues are generated from the collection, transfer, recycling and disposal of non-hazardous solid waste and the treatment, recovery and disposal of non-hazardous E&P waste. No single contract or customer accounted for more than 10% of the Company’s total revenues at the consolidated or reportable segment level during the periods presented. The Company manages its operations through five geographic operating segments and its E&P segment , which includes the majority of the Company’s E&P waste treatment and disposal operations. The Company’s five geographic operating segments and its E&P segment comprise the Company’s reportable segments. Each operating segment is responsible for managing several vertically integrated operations, which are comprised of districts. The Company’s Southern segment services customers located in Alabama, Arkansas, Florida, Louisiana, Mississippi, southern Oklahoma, western Tennessee and Texas; the Company’s Western segment services customers located in Alaska, California, Idaho, Montana, Nevada, Oregon, Washington and western Wyoming; the Company’s Eastern segment services customers located in Illinois, Iowa, Kentucky, Maryland, New Jersey, New York, North Carolina, Pennsylvania, Rhode Island, South Carolina, eastern Tennessee, Vermont, Virginia and Wisconsin; the Company’s Canada segment services customers located in the state of Michigan and in the provinces of Alberta, British Columbia, Manitoba, Ontario, Québec and Saskatchewan; and the Company’s Central segment services customers located in Arizona, Colorado, Kansas, Minnesota, Missouri, Nebraska, New Mexico, Oklahoma, South Dakota, western Texas, Utah and eastern Wyoming. The E&P segment services E&P customers located in Arkansas, Louisiana, New Mexico, North Dakota, Oklahoma, Texas, Wyoming and along the Gulf of Mexico. The Company’s Chief Operating Decision Maker evaluates operating segment profitability and determines resource allocations based on several factors, of which the primary financial measure is segment EBITDA. The Company defines segment EBITDA as earnings before interest, taxes, depreciation, amortization, impairments and other operating items, other income (expense) and foreign currency transaction gain (loss). Segment EBITDA is not a measure of operating income, operating performance or liquidity under GAAP and may not be comparable to similarly titled measures reported by other companies. The Company’s management uses segment EBITDA in the evaluation of segment operating performance as it is a profit measure that is generally within the control of the operating segments. A reconciliation of segment EBITDA to Income before income tax provision is included at the end of this Note 11. Summarized financial information concerning the Company’s reportable segments for the three and nine months ended September 30, 2018 and 2017, is shown in the following tables:  Three Months Ended September 30, 2018 Revenue Intercompany Revenue (b) Reported Revenue Segment EBITDA (c)  Southern $ 321,306 $ (38,266) $ 283,040 $ 70,159  Western 303,614 (32,596) 271,018 86,174  Eastern 353,844 (64,347) 289,497 83,721  Canada 211,682 (24,628) 187,054 68,819  Central 213,492 (28,221) 185,271 70,288  E&P 67,348 (2,118) 65,230 35,099  Corporate (a) - - - (8,286)  $ 1,471,286 $ (190,176) $ 1,281,110 $ 405,974   Three Months Ended September 30, 2017 Revenue Intercompany Revenue (b) Reported Revenue Segment EBITDA (c)  Southern $ 317,059 $ (36,531) $ 280,528 $ 63,171  Western 292,222 (30,345) 261,877 84,861  Eastern 292,124 (45,857) 246,267 74,018  Canada 224,166 (27,111) 197,055 74,369  Central 190,210 (23,850) 166,360 64,607  E&P 56,209 (1,818) 54,391 27,881  Corporate (a) - - - (5,751)  $ 1,371,990 $ (165,512) $ 1,206,478 $ 383,156   Nine Months Ended September 30, 2018 Revenue Intercompany Revenue (b) Reported Revenue Segment EBITDA (c)  Southern $ 951,313 $ (111,824) $ 839,489 $ 207,853  Western 874,464 (94,584) 779,880 240,006  Eastern 966,571 (164,253) 802,318 225,950  Canada 615,157 (71,290) 543,867 195,390  Central 591,417 (77,337) 514,080 191,840  E&P 186,734 (5,159) 181,575 95,009  Corporate (a) - - - (14,368)  $ 4,185,656 $ (524,447) $ 3,661,209 $ 1,141,680   Nine Months Ended September 30, 2017 Revenue Intercompany Revenue (b) Reported Revenue Segment EBITDA (c)  Southern $ 957,506 $ (111,472) $ 846,034 $ 199,280  Western 845,176 (90,217) 754,959 247,475  Eastern 851,880 (133,578) 718,302 209,315  Canada 621,995 (75,846) 546,149 200,283  Central 536,803 (66,716) 470,087 177,975  E&P 143,951 (6,169) 137,782 63,518  Corporate (a) - - - (32,535)  $ 3,957,311 $ (483,998) $ 3,473,313 $ 1,065,311 ____________________ (a) Corporate functions include accounting, legal, tax, treasury, information technology, risk management, human resources, training and other administrative functions. Amounts reflected are net of allocations to the six operating segments. (b) Intercompany revenues reflect each segment’s total intercompany sales, including intercompany sales within a segment and between segments. Transactions within and between segments are generally made on a basis intended to reflect the market value of the service. (c) For those items included in the determination of segment EBITDA, the accounting policies of the segments are the same as those described in the Company’s most recent Annual Report on Form 10-K.  Total assets for each of the Company’s reportable segments at September 30, 2018 and December 31, 2017, were as follows:    September 30, 2018 December 31, 2017  Southern $ 2,778,123 $ 2,718,296  Western 1,583,561 1,573,955  Eastern 2,348,438 2,024,527  Canada 2,562,659 2,677,557  Central 1,452,607 1,297,118  E&P 974,049 981,980  Corporate 492,629 741,248  Total Assets $ 12,192,066 $ 12,014,681  The following tables show changes in goodwill during the nine months ended September 30, 2018 and 2017, by reportable segment:     Southern Western Eastern Canada Central E&P Total  Balance as of December 31, 2017 $ 1,436,320 $ 397,508 $ 804,133 $ 1,575,538 $ 468,275 $ - $ 4,681,774  Goodwill acquired 4,800 666 122,136 151 42,197 - 169,950  Goodwill adjustment for assets held for sale 10,194 - - - - - 10,194  Impact of changes in foreign currency - - - (48,622) - - (48,622)  Balance as of September 30, 2018 $ 1,451,314 $ 398,174 $ 926,269 $ 1,527,067 $ 510,472 $ - $ 4,813,296     Southern Western Eastern Canada Central E&P Total  Balance as of December 31, 2016 $ 1,470,023 $ 376,537 $ 533,160 $ 1,465,274 $ 467,924 $ 77,343 $ 4,390,261  Goodwill acquired 7,484 20,906 272,501 7,127 1,013 - 309,031  Goodwill divested (31,543) - (4,276) - (667) - (36,486)  Impairment loss - - - - - (77,343) (77,343)  Goodwill adjustment for assets sold 2,205 - 321 - - - 2,526  Goodwill adjustment for assets held for sale (11,080) - - - - - (11,080)  Impact of changes in foreign currency - - - 111,439 - - 111,439  Balance as of September 30, 2017 $ 1,437,089 $ 397,443 $ 801,706 $ 1,583,840 $ 468,270 $ - $ 4,688,348   A reconciliation of the Company’s primary measure of segment profitability (segment EBITDA) to Income before income tax provision in the Condensed Consolidated Statements of Net Income is as follows:   Three months ended September 30, Nine months ended September 30,  2018 2017 2018 2017  Southern segment EBITDA $ 70,159 $ 63,171 $ 207,853 $ 199,280  Western segment EBITDA 86,174 84,861 240,006 247,475  Eastern segment EBITDA 83,721 74,018 225,950 209,315  Canada segment EBITDA 68,819 74,369 195,390 200,283  Central segment EBITDA 70,288 64,607 191,840 177,975  E&P segment EBITDA 35,099 27,881 95,009 63,518  Subtotal reportable segments 414,260 388,907 1,156,048 1,097,846  Unallocated corporate overhead (8,286) (5,751) (14,368) (32,535)  Depreciation (148,232) (136,941) (423,866) (395,008)  Amortization of intangibles (26,871) (26,613) (79,444) (76,886)  Impairments and other operating items 1,998 (832) (6,106) (141,333)  Interest expense (32,078) (32,471) (96,874) (92,763)  Interest income 1,467 1,656 3,677 3,131  Other income, net 732 1,709 2,376 3,561  Foreign currency transaction loss (132) (1,864) (323) (3,502)  Income before income tax provision $ 202,858 $ 187,800 $ 541,120 $ 362,511  

Derivative Financial Instrument

Derivative Financial Instruments	9 Months Ended
	Sep. 30, 2018
Derivative Financial Instruments [Abstract]
Derivative Financial Instruments	12. DERIVATIVE FINANCIAL INSTRUMENTS The Company recognizes all derivatives on the Condensed Consolidated Balance Sheets at fair value. All of the Company’s derivatives have been designated as cash flow hedges; therefore, the effective portion of the changes in the fair value of derivatives will be recognized in accumulated other comprehensive income (loss) (“AOCIL”) until the hedged item is recognized in earnings. The ineffective portion of the changes in the fair value of derivatives will be immediately recognized in earnings. The Company classifies cash inflows and outflows from derivatives within operating activities on the Condensed Consolidated Statements of Cash Flows. One of the Company’s objectives for utilizing derivative instruments is to reduce its exposure to fluctuations in cash flows due to changes in the variable interest rates of certain borrowings under the Credit Agreement. The Company’s strategy to achieve that objective involves entering into interest rate swaps. The interest rate swaps outstanding at September 30, 2018 were specifically designated to the Credit Agreement and accounted for as cash flow hedges. At September 30, 2018, the Company’s derivative instruments included 16 interest rate swap agreements as follows:   Date Entered Notional Amount Fixed Interest Rate Paid* Variable Interest Rate Received Effective Date Expiration Date  April 2014 $ 100,000 1.800% 1-month LIBOR July 2014 July 2019  May 2014 $ 50,000 2.344% 1-month LIBOR October 2015 October 2020  May 2014 $ 25,000 2.326% 1-month LIBOR October 2015 October 2020  May 2014 $ 50,000 2.350% 1-month LIBOR October 2015 October 2020  May 2014 $ 50,000 2.350% 1-month LIBOR October 2015 October 2020  April 2016 $ 100,000 1.000% 1-month LIBOR February 2017 February 2020  June 2016 $ 75,000 0.850% 1-month LIBOR February 2017 February 2020  June 2016 $ 150,000 0.950% 1-month LIBOR January 2018 January 2021  June 2016 $ 150,000 0.950% 1-month LIBOR January 2018 January 2021  July 2016 $ 50,000 0.900% 1-month LIBOR January 2018 January 2021  July 2016 $ 50,000 0.890% 1-month LIBOR January 2018 January 2021  August 2017 $ 100,000 1.900% 1-month LIBOR July 2019 July 2022  August 2017 $ 200,000 2.200% 1-month LIBOR October 2020 October 2025  August 2017 $ 150,000 1.950% 1-month LIBOR February 2020 February 2023  June 2018 $ 200,000 2.925% 1-month LIBOR October 2020 October 2025  June 2018 $ 200,000 2.925% 1-month LIBOR October 2020 October 2025 ____________________ * Plus applicable margin. Another of the Company’s objectives for utilizing derivative instruments is to reduce its exposure to fluctuations in cash flows due to changes in the price of diesel fuel. The Company’s strategy to achieve that objective involves periodically entering into fuel hedges that are specifically designated to certain forecasted diesel fuel purchases and accounted for as cash flow hedges. At September 30, 2018, the Company’s derivative instruments included one fuel hedge agreement as follows:  Date Entered Notional Amount (in gallons per month) Diesel Rate Paid Fixed (per gallon) Diesel Rate Received Variable Effective Date Expiration Date  July 2016 1,000,000 $2.6345 DOE Diesel Fuel Index* January 2018 December 2018 ____________________ * If the national U.S. on-highway average price for a gallon of diesel fuel (“average price”), as published by the U.S. Department of Energy (“DOE”), exceeds the contract price per gallon, the Company receives the difference between the average price and the contract price (multiplied by the notional number of gallons) from the counterparty. If the average price is less than the contract price per gallon, the Company pays the difference to the counterparty.  The fair values of derivative instruments designated as cash flow hedges as of September 30, 2018, were as follows:  Derivatives Designated as Cash Asset Derivatives Liability Derivatives Flow Hedges Balance Sheet Location Fair Value Balance Sheet Location Fair Value  Interest rate swaps Prepaid expenses and other current assets (a) $ 11,380 Other long-term liabilities $ -  Other assets, net 25,834   Fuel hedges Prepaid expenses and other current assets (b) 2,189  Total derivatives designated as cash flow hedges $ 39,403 $ - ____________________ (a) Represents the estimated amount of the existing unrealized gains on interest rate swaps as of September 30, 2018 (based on the interest rate yield curve at that date), included in AOCIL expected to be reclassified into pre-tax earnings within the next 12 months. The actual amounts reclassified into earnings are dependent on future movements in interest rates. (b) Represents the estimated amount of the existing unrealized gains on the fuel hedge as of September 30, 2018 (based on the forward DOE diesel fuel index curve at that date), included in AOCIL expected to be reclassified into pre-tax earnings within the next 12 months. The actual amounts reclassified into earnings are dependent on future movements in diesel fuel prices.  The fair values of derivative instruments designated as cash flow hedges as of December 31, 2017, were as follows:  Derivatives Designated as Cash Asset Derivatives Liability Derivatives Flow Hedges Balance Sheet Location Fair Value Balance Sheet Location Fair Value  Interest rate swaps Prepaid expenses and other current assets $ 5,193 Accrued liabilities $ (903)  Other assets, net 15,182 Other long-term liabilities (493)   Fuel hedges Prepaid expenses and other current assets 3,880  Total derivatives designated as cash flow hedges $ 24,255 $ (1,396)   The following table summarizes the impact of the Company’s cash flow hedges on the results of operations, comprehensive income (loss) and AOCIL for the three and nine months ended September 30, 2018 and 2017:  Derivatives Designated as Cash Flow Hedges Amount of Gain or (Loss) Recognized as AOCIL on Derivatives, Net of Tax (Effective Portion) (a) Statement of Net Income Classification Amount of (Gain) or Loss Reclassified from AOCIL into Earnings, Net of Tax (Effective Portion) (b),(c)  Three Months Ended September 30, Three Months Ended September 30,  2018 2017 2018 2017  Interest rate swaps $ 634 $ (361) Interest expense $ 3,145 $ 376  Fuel hedges 222 1,680 Cost of operations (1,359) 487  Total $ 856 $ 1,319 $ 1,786 $ 863   Derivatives Designated as Cash Flow Hedges Amount of Gain or (Loss) Recognized as AOCIL on Derivatives, Net of Tax (Effective Portion) (a) Statement of Net Income Classification Amount of (Gain) or Loss Reclassified from AOCIL into Earnings, Net of Tax (Effective Portion) (b),(c)  Nine Months Ended September30, Nine Months Ended September 30,  2018 2017 2018 2017  Interest rate swaps $ 11,634 $ 224 Interest expense $ 1,769 $ 1,729  Fuel hedges 2,226 (1,030) Cost of operations (3,490) 1,704  Total $ 13,860 $ (806) $ (1,721) $ 3,433 ___________________ (a) In accordance with the derivatives and hedging guidance, the effective portions of the changes in fair values of interest rate swaps and fuel hedges have been recorded in equity as a component of AOCIL. As the critical terms of the interest rate swaps match the underlying debt being hedged, no ineffectiveness is recognized on these swaps and, therefore, all unrealized changes in fair value are recorded in AOCIL. Because changes in the actual price of diesel fuel and changes in the DOE index price do not offset exactly each reporting period, the Company assesses whether the fuel hedges are highly effective using the cumulative dollar offset approach. (b) Amounts reclassified from AOCIL into earnings related to realized gains and losses on interest rate swaps are recognized when interest payments or receipts occur related to the swap contracts, which correspond to when interest payments are made on the Company’s hedged debt. (c) Amounts reclassified from AOCIL into earnings related to realized gains and losses on the fuel hedges are recognized when settlement payments or receipts occur related to the hedge contracts, which correspond to when the underlying fuel is consumed. The Company measures and records ineffectiveness on the fuel hedges in Cost of operations in the Condensed Consolidated Statements of Net Income on a monthly basis based on the difference between the DOE index price and the actual price of diesel fuel purchased, multiplied by the notional number of gallons on the contracts. There was no significant ineffectiveness recognized on the fuel hedges during the nine months ended September 30, 2018 and 2017. See Note 16 for further discussion on the impact of the Company’s hedge accounting to its consolidated comprehensive income (loss) and AOCIL. 

Fair Value of Financial Instrum

Fair Value of Financial Instruments	9 Months Ended
	Sep. 30, 2018
Fair Value [Abstract]
Fair Value of Financial Instruments	13. FAIR VALUE OF FINANCIAL INSTRUMENTS The Company’s financial instruments consist primarily of cash and equivalents, trade receivables, restricted cash and investments, trade payables, debt instruments, contingent consideration obligations, interest rate swaps and fuel hedges. As of September 30, 2018 and December 31, 2017, the carrying values of cash and equivalents, trade receivables, restricted cash and investments, trade payables and contingent consideration are considered to be representative of their respective fair values. The carrying values of the Company’s debt instruments, excluding certain notes as listed in the table below, approximate their fair values as of September 30, 2018 and December 31, 2017, based on current borrowing rates, current remaining average life to maturity and borrower credit quality for similar types of borrowing arrangements, and are classified as Level 2 within the fair value hierarchy. The carrying values and fair values of the Company’s debt instruments where the carrying values do not approximate their fair values as of September 30, 2018 and December 31, 2017, are as follows:   Carrying Value at Fair Value* at  September 30, 2018 December 31, 2017 September 30, 2018 December 31, 2017  2018 Senior Notes $ - $ 50,000 $ - $ 50,223  2019 Senior Notes $ 175,000 $ 175,000 $ 178,150 $ 182,547  2021 Senior Notes $ 100,000 $ 100,000 $ 101,780 $ 104,985  New 2021 Senior Notes $ 150,000 $ 150,000 $ 144,299 $ 146,855  2022 Senior Notes $ 125,000 $ 125,000 $ 121,062 $ 124,532  2023 Senior Notes $ 200,000 $ 200,000 $ 188,988 $ 194,660  2024 Senior Notes $ 150,000 $ 150,000 $ 143,651 $ 149,133  2025 Senior Notes $ 375,000 $ 375,000 $ 358,141 $ 375,311  2026 Senior Notes $ 400,000 $ 400,000 $ 369,921 $ 388,760  2027 Senior Notes $ 250,000 $ 250,000 $ 236,409 $ 250,029 ______________________ * Senior Notes are classified as Level 2 within the fair value hierarchy. Fair value is based on quotes of bonds with similar ratings in similar industries. For details on the fair value of the Company’s interest rate swaps, fuel hedges, restricted cash and investments and contingent consideration, refer to Note 15. 

Net Income Per Share Informatio

Net Income Per Share Information	9 Months Ended
	Sep. 30, 2018
Net Income Per Share Information [Abstract]
Net Income Per Share Information	14. NET INCOME PER SHARE INFORMATION The following table sets forth the calculation of the numerator and denominator used in the computation of basic and diluted net income per common share attributable to the Company’s shareholders for the three and nine months ended September 30, 2018 and 2017:   Three months ended September 30, Nine months ended September 30,  2018 2017 2018 2017 Numerator:  Net income attributable to Waste Connections for basic and diluted earnings per share $ 150,843 $ 123,227 $ 414,393 $ 261,732  Denominator:  Basic shares outstanding 263,628,838 263,443,064 263,657,274 263,298,839  Dilutive effect of equity-based awards 765,919 856,408 719,046 810,544  Diluted shares outstanding 264,394,757 264,299,472 264,376,320 264,109,383  

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2018
Fair Value [Abstract]
Fair Value Measurements	15. FAIR VALUE MEASUREMENTS The Company uses a three-tier fair value hierarchy to classify and disclose all assets and liabilities measured at fair value on a recurring basis in periods subsequent to their initial measurement. These tiers include: Level 1, defined as quoted market prices in active markets for identical assets or liabilities; Level 2, defined as inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities, quoted prices in markets that are not active, model-based valuation techniques for which all significant assumptions are observable in the market, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities; and Level 3, defined as unobservable inputs that are not corroborated by market data. The Company’s financial assets and liabilities recorded at fair value on a recurring basis include derivative instruments and restricted cash and investments. The Company’s derivative instruments are pay-fixed, receive-variable interest rate swaps and pay-fixed, receive-variable diesel fuel hedges. The Company’s interest rate swaps are recorded at their estimated fair values based on quotes received from financial institutions that trade these contracts. The Company verifies the reasonableness of these quotes using similar quotes from another financial institution as of each date for which financial statements are prepared. The Company uses a discounted cash flow (“DCF”) model to determine the estimated fair value of the diesel fuel hedges. The assumptions used in preparing the DCF model include: (i) estimates for the forward DOE index curve; and (ii) the discount rate based on risk-free interest rates over the term of the hedge contracts. The DOE index curve used in the DCF model was obtained from financial institutions that trade these contracts and ranged from $3.36 to $3.39 at September 30, 2018 and from $2.95 to $3.00 at December 31, 2017. The weighted average DOE index curve used in the DCF model was $3.38 and $2.96 at September 30, 2018 and December 31, 2017, respectively. Significant increases (decreases) in the forward DOE index curve would result in a significantly higher (lower) fair value measurement. For the Company’s interest rate swaps and fuel hedges, the Company also considers the Company’s creditworthiness in its determination of the fair value measurement of these instruments in a net liability position and the counterparties’ creditworthiness in its determination of the fair value measurement of these instruments in a net asset position. The Company’s restricted cash and investments are valued at quoted market prices in active markets for similar assets, which the Company receives from the financial institutions that hold such investments on its behalf. The Company’s restricted cash and investments measured at fair value are invested primarily in U.S. government and agency securities, money market accounts and Canadian bankers’ acceptance notes. The Company’s assets and liabilities measured at fair value on a recurring basis at September 30, 2018 and December 31, 2017, were as follows:   Fair Value Measurement at September 30, 2018 Using  Total Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3)  Interest rate swap derivative instruments – net asset position $ 37,214 $ - $ 37,214 $ -  Fuel hedge derivative instrument – net asset position $ 2,189 $ - $ - $ 2,189  Restricted cash and investments $ 126,221 $ - $ 126,221 $ -  Contingent consideration $ (55,024) $ - $ - $ (55,024)    Fair Value Measurement at December 31, 2017 Using  Total Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3)  Interest rate swap derivative instruments – net asset position $ 18,979 $ - $ 18,979 $ -  Fuel hedge derivative instrument – net asset position $ 3,880 $ - $ - $ 3,880  Restricted cash and investments $ 165,592 $ - $ 165,592 $ -  Contingent consideration $ (47,285) $ - $ - $ (47,285)  The following table summarizes the changes in the fair value for Level 3 derivatives for the nine months ended September 30, 2018 and 2017:    Nine Months Ended September 30,  2018 2017  Beginning balance $ 3,880 $ (264)  Realized (gains) losses included in earnings (4,647) 2,765  Unrealized gains (losses) included in AOCIL 2,956 (1,672)  Ending balance $ 2,189 $ 829   The following table summarizes the changes in the fair value for Level 3 liabilities related to contingent consideration for the nine months ended September 30, 2018 and 2017:   Nine Months Ended September 30,  2018 2017  Beginning balance $ 47,285 $ 51,826  Contingent consideration recorded at acquisition date 11,669 35  Payment of contingent consideration recorded at acquisition date (5,459) (5,840)  Payment of contingent consideration recorded in earnings (11) -  Adjustments to contingent consideration 349 17,754  Reclass earned contingent consideration to accrued liabilities - (20,464)  Interest accretion expense 1,308 1,381  Foreign currency translation adjustment (117) 263  Ending balance $ 55,024 $ 44,955   

Other Comprehensive Income (Los

Other Comprehensive Income (Loss)	9 Months Ended
	Sep. 30, 2018
Other Comprehensive Income (Loss) [Abstract]
Other Comprehensive Income (Loss)	16. OTHER COMPREHENSIVE INCOME (LOSS) O ther comprehensive income (loss) includes changes in the fair value of interest rate swaps and fuel hedges that qualify for hedge accounting. The components of other comprehensive income (loss) and related tax effects for the three and nine months ended September 30, 2018 and 2017 are as follows:   Three months ended September 30, 2018  Gross Tax effect Net of tax  Interest rate swap amounts reclassified into interest expense $ 4,279 $ (1,134) $ 3,145  Fuel hedge amounts reclassified into cost of operations (1,810) 451 (1,359)  Changes in fair value of interest rate swaps 863 (229) 634  Changes in fair value of fuel hedge 295 (73) 222  Foreign currency translation adjustment 35,455 - 35,455  $ 39,082 $ (985) $ 38,097     Three months ended September 30, 2017  Gross Tax effect Net of tax  Interest rate swap amounts reclassified into interest expense $ 511 $ (135) $ 376  Fuel hedge amounts reclassified into cost of operations 789 (302) 487  Changes in fair value of interest rate swaps 2,181 (2,542) (361)  Changes in fair value of fuel hedges 2,717 (1,037) 1,680  Foreign currency translation adjustment 84,500 - 84,500  $ 90,698 $ (4,016) $ 86,682     Nine months ended September 30, 2018  Gross Tax effect Net of tax  Interest rate swap amounts reclassified into interest expense $ 2,407 $ (638) $ 1,769  Fuel hedge amounts reclassified into cost of operations (4,647) 1,157 (3,490)  Changes in fair value of interest rate swaps 15,828 (4,194) 11,634  Changes in fair value of fuel hedge 2,956 (730) 2,226  Foreign currency translation adjustment (67,349) - (67,349)  $ (50,805) $ (4,405) $ (55,210)     Nine months ended September 30, 2017  Gross Tax effect Net of tax  Interest rate swap amounts reclassified into interest expense $ 2,352 $ (623) $ 1,729  Fuel hedge amounts reclassified into cost of operations 2,765 (1,061) 1,704  Changes in fair value of interest rate swaps 305 (81) 224  Changes in fair value of fuel hedges (1,672) 642 (1,030)  Foreign currency translation adjustment 155,153 - 155,153  $ 158,903 $ (1,123) $ 157,780   A rollforward of the amounts included in AOCIL, net of taxes, for the nine months ended September 30, 2018 and 2017, is as follows:   Fuel Hedges Interest Rate Swaps Foreign Currency Translation Adjustment Accumulated Other Comprehensive Income (Loss)  Balance at December 31, 2017 $ 2,907 $ 13,951 $ 91,555 $ 108,413  Amounts reclassified into earnings (3,490) 1,769 - (1,721)  Changes in fair value 2,226 11,634 - 13,860  Foreign currency translation adjustment - - (67,349) (67,349)  Balance at September 30, 2018 $ 1,643 $ 27,354 $ 24,206 $ 53,203     Fuel Hedges Interest Rate Swaps Foreign Currency Translation Adjustment Accumulated Other Comprehensive Income (Loss)  Balance at December 31, 2016 $ (164) $ 8,094 $ (50,931) $ (43,001)  Amounts reclassified into earnings 1,704 1,729 - 3,433  Changes in fair value (1,030) 224 - (806)  Foreign currency translation adjustment - - 155,153 155,153  Balance at September 30, 2017 $ 510 $ 10,047 $ 104,222 $ 114,779  See Note 12 for further discussion on the Company’s derivative instruments.

Shareholders' Equity

Shareholders' Equity	9 Months Ended
	Sep. 30, 2018
Shareholders' Equity [Abstract]
Shareholders' Equity	17. SHAREHOLDERS' EQUITY Share-Based Compensation Restricted Share Units A summary of activity related to restricted share units (“RSUs”) during the nine-month period ended September 30, 2018, is presented below:   Unvested Shares  Outstanding at December 31, 2017 1,042,014  Granted 496,217  Forfeited (53,063)  Vested and issued (480,577)  Vested and deferred (3,653)  Outstanding at September 30, 2018 1,000,938   The weighted average grant-date fair value per share for the common shares underlying the RSUs granted during the nine-month period ended September 30, 2018 was $69.22 . Recipients of RSUs who participate in the Company’s Nonqualified Deferred Compensation Plan may have elected in years prior to 2015 to defer some or all of their RSUs as they vest until a specified date or dates they choose. At the end of the deferral periods, unless a qualified participant makes certain other elections, the Company issues to recipients who deferred their RSUs common shares of the Company underlying the deferred RSUs. At September 30, 2018 and 2017, the Company had 264,374 and 352,214 vested deferred RSUs outstanding, respectively. Performance-Based Restricted Share Units A summary of activity related to performance-based restricted share units (“PSUs”) during the nine-month period ended September 30, 2018, is presented below:   Unvested Shares  Outstanding at December 31, 2017 514,461  Granted 178,377  Forfeited (2,071)  Vested and issued (154,181)  Outstanding at September 30, 2018 536,586   During the nine months ended September 30, 2018, the Compensation Committee granted PSUs with three -year performance-based metrics that the Company must meet before those awards may be earned, and the performance period for those grants ends on December 31, 2020 . During the same period, the Compensation Committee also granted PSUs with a one -year performance-based metric that the Company must meet before those awards may be earned, with the awards then subject to time-based vesting for the remaining three years of their four -year vesting period. The Compensation Committee will determine the achievement of performance results and corresponding vesting of PSUs for each performance period. The weighted average grant-date fair value per share for the common shares underlying all PSUs granted during the nine-month period ended September 30, 2018 was $69.04 . Deferred Share Units A summary of activity related to deferred share units (“DSUs”) during the nine-month period ended September 30, 2018, is presented below:   Vested Shares  Outstanding at December 31, 2017 13,138  Granted 4,038  Outstanding at September 30, 2018 17,176   The DSUs consist of a combination of DSU grants outstanding under the Progressive Waste share-based compensation plans that were continued by the Company following the Progressive Waste acquisition and DSUs granted by the Company since the Progressive Waste acquisition. The weighted average grant-date fair value per share for the common shares underlying the DSUs granted during the nine-month period ended September 30, 2018 was $70.47 . Other Restricted Share Units RSU grants outstanding under the Progressive Waste share-based compensation plans were continued by the Company following the Progressive Waste acquisition and allow for the issuance of shares or cash settlement to employees upon vesting. A summary of activity related to Progressive Waste RSUs during the nine-month period ended September 30, 2018, is presented below:   Outstanding at December 31, 2017 158,510  Cash settled (27,059)  Forfeited (2,435)  Outstanding at September 30, 2018 129,016  A summary of vesting activity related to Progressive Waste RSUs during the nine-month period ended September 30, 2018, is presented below:   Vested at December 31, 2017 138,054  Vested over remaining service period 14,695  Cash settled (27,059)  Forfeited (2,435)  Vested at September 30, 2018 123,255  No RSUs under the Progressive Waste share-based compensation plans were granted subsequent to June 1, 2016. Other Performance-Based Restricted Share Units PSU grants outstanding under the Progressive Waste share-based compensation plans were continued by the Company following the Progressive Waste acquisition and allow for cash settlement only to employees upon vesting based on achieving target results. A summary of activity related to Progressive Waste PSUs during the nine-month period ended September 30, 2018, is presented below:   Outstanding at December 31, 2017 55,602  Cash settled, net of notional dividend (27,033)  Forfeited (1,909)  Outstanding at September 30, 2018 26,660  A summary of vesting activity related to Progressive Waste PSUs during the nine-month period ended September 30, 2018, is presented below:   Vested at December 31, 2017 28,407  Vested over remaining service period 25,417  Cash settled, net of notional dividend (27,033)  Forfeited (1,909)  Vested at September 30, 2018 24,882  No PSUs under the Progressive Waste share-based compensation plans were granted subsequent to June 1, 2016. Share Based Options Share based options outstanding under the Progressive Waste share-based compensation plans were continued by the Company following the Progressive Waste acquisition and allow for the issuance of shares or cash settlement to employees upon vesting. A summary of activity related to Progressive Waste share based options during the nine-month period ended September 30, 2018, is presented below:   Outstanding at December 31, 2017 236,616  Cash settled (71,460)  Outstanding at September 30, 2018 165,156  No share based options under the Progressive Waste share-based compensation plans were granted subsequent to June 1, 2016. All outstanding share based options were vested as of December 31, 2017. Normal Course Issuer Bid On July 24, 2018, the Board of Directors of the Company approved, subject to receipt of regulatory approvals, the annual renewal of the Company’s normal course issuer bid (the “NCIB”) to purchase up to 13,174,976 of the Company’s common shares during the period of August 8, 2018 to August 7, 2019 or until such earlier time as the NCIB is completed or terminated at the option of the Company. The renewal followed on the conclusion of the Company’s NCIB that expired August 7, 2018. The Company received Toronto Stock Exchange (the “TSX”) approval for its annual renewal of the NCIB on August 2, 2018. Under the NCIB, the Company may make share repurchases only in the open market, including on the New York Stock Exchange (the “NYSE”), the TSX, and/or alternative Canadian trading systems, at the prevailing market price at the time of the transaction. In accordance with TSX rules, any daily repurchases made through the TSX and alternative Canadian trading systems is limited to a maximum of 71,114 common shares, which represents 25% of the average daily trading volume on the TSX of 284,459 common shares for the period from February 1, 2018 to July 31, 2018. The TSX rules also allow the Company to purchase, once a week, a block of common shares not owned by any insiders, which may exceed such daily limit. The maximum number of shares that can be purchased per day on the NYSE will be 25% of the average daily trading volume for the four calendar weeks preceding the date of purchase, subject to certain exceptions for block purchases. The timing and amounts of any repurchases pursuant to the NCIB will depend on many factors, including the Company’s capital structure, the market price of the common shares and overall market conditions. All common shares purchased under the NCIB shall be immediately cancelled following their repurchase. During the nine months ended September 30, 2018, the Company repurchased 594,474 common shares pursuant to its NCIB in effect during such period at an aggregate cost of $42,040 . For the nine months ended September 30, 2017, the Company did not repurchase any common shares pursuant to the NCIB in effect during that period. As of September 30, 2018, the remaining maximum number of shares available for repurchase under the NCIB was 12,587,332 . Cash Dividend In October 2017, the Company announced that its Board of Directors increased its regular quarterly cash dividend by $0.02 , from $0.12 to $0.14 per share. Cash dividends of $110,447 and $95,201 were paid during the nine months ended September 30, 2018 and 2017, respectively.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2018
Commitments and Contingencies [Abstract]
Commitments and Contingencies	18. COMMITMENTS AND CONTINGENCIES In the normal course of its business and as a result of the extensive governmental regulation of the solid waste and E&P waste industries, the Company is subject to various judicial and administrative proceedings involving Canadian regulatory authorities as well as U.S. federal, state and local agencies. In these proceedings, an agency may subpoena the Company for records, or seek to impose fines on the Company or revoke or deny renewal of an authorization held by the Company, including an operating permit. From time to time, the Company may also be subject to actions brought by special interest or other groups, adjacent landowners or residents in connection with the permitting and licensing of landfills, transfer stations, and E&P waste treatment, recovery and disposal operations, or alleging environmental damage or violations of the permits and licenses pursuant to which the Company operates. In addition, the Company is a party to various claims and suits pending for alleged damages to persons and property, alleged violations of certain laws and alleged liabilities arising out of matters occurring during the normal operation of the Company’s business. Except as noted in the matters described below, as of September 30, 2018, there is no current proceeding or litigation involving the Company or its property that the Company believes could have a material adverse effect on its business, financial condition, results of operations or cash flows. Lower Duwamish Waterway Superfund Site Allocation Process In November 2012, the Company’s subsidiary, Northwest Container Services, Inc. (“NWCS”), was named by the U.S. Environmental Protection Agency, Region 10 (the “EPA”) as a potentially responsible party (“PRP”), along with more than 100 others, under the Comprehensive Environmental Response, Compensation and Liability Act (“CERCLA” or the “Superfund” law) with respect to the Lower Duwamish Waterway Superfund Site (the “LDW Site”). Listed on the National Priorities List in 2001, the LDW Site is a five-mile stretch of the Duwamish River flowing into Elliott Bay in Seattle, Washington. A group of PRPs known as the Lower Duwamish Working Group (“LDWG”) and consisting of the City of Seattle, King County, the Port of Seattle, and Boeing Company conducted a Remedial Investigation/Feasibility Study for the LDW Site. On December 2, 2014, the EPA issued its Record of Decision (the “ROD”) describing the selected clean-up remedy, and therein estimated that clean-up costs (in present value dollars as of November 2014) would total approximately $342,000 . However, it is possible that additional costs could be incurred based upon various factors. The EPA estimates that it will take seven years to implement the clean-up. The ROD also requires ten years of monitoring following the clean-up, and provides that if clean-up goals have not been met by the end of this period, then additional clean-up activities, at additional cost, may be required at that time. Implementation of the clean-up will not begin until after the ongoing Early Action Area (“EAA”) clean-ups have been completed. Typically, costs for monitoring may be in addition to those expended for the clean-up. While three of the EAA clean-ups have been completed to date, some work remains to be done on three other EAAs. Implementation of the clean-up also must await additional baseline sampling throughout the LDW Site and the preparation of a remedial design for performing the clean-up. On April 27, 2016, the LDWG entered into a third amendment of its Administrative Order on Consent with the EPA (the “AOC 3”) in which it agreed to perform the additional baseline sediment sampling and certain technical studies needed to prepare the actual remedial design. The LDWG and EPA entered into a fourth amendment to the AOC in July 2018 primarily addressing development of a proposed remedy for the upper reach of the LDW Site, river mile 3 to river mile 5. On August 16, 2016, the EPA sent individual letters to each of the PRPs for the LDW Site, including NWCS, stating that it expects to initiate negotiations with all PRPs in early 2018 relating to a Remedial Design/Remedial Action (“RD/RA”) Consent Decree. An RD/RA Consent Decree provides for the cleanup of the entire site and is often referred to as a “global settlement.” In August 2014, NWCS entered into an Alternative Dispute Resolution Memorandum of Agreement with several dozen other PRPs and a neutral allocator to conduct a confidential and non-binding allocation of certain past response costs allegedly incurred at the LDW Site as well as the anticipated future response costs associated with the clean-up. The pre-remedial design work under the AOC 3 is now not expected to conclude until the end of 2019, and in March 2017, the PRPs provided the EPA with notice that the allocation is not scheduled to conclude until mid-2019. With recent extensions, the allocation is now scheduled to conclude in early 2020. In June 2017, attorneys for the EPA informed attorneys for several PRPs that the EPA expected to begin RD/RA negotiations in the late summer or early fall of 2018. Those negotiations have not been scheduled and there is no recent indication from the EPA regarding when they will begin. The Company cannot provide assurance that the EPA’s schedule can be met or will be adjusted. NWCS is defending itself vigorously in this confidential allocation process. At this point, the Company is not able to determine the likelihood of the allocation process being completed as intended by the participating PRPs, its specific allocation, or the likelihood of the parties then negotiating a global settlement with the EPA. Thus, NWCS cannot reasonably determine the likelihood of any outcome in this matter, including its potential liability. On February 11, 2016, NWCS received a letter (the “Letter”) from the United States Department of Commerce, National Oceanic and Atmospheric Administration (“NOAA”), describing certain investigatory activities conducted by the Elliott Bay Trustee Council (the “Council”). The Council consists of all of the natural resources trustees for the LDW Site as well as two nearby Superfund sites, the Harbor Island site and the Lockheed West site. The members of the Council include the United States, on behalf of the U.S. National Oceanic and Atmospheric Administration and the U.S. Department of the Interior, the Washington State Department of Ecology, and the Suquamish and Muckleshoot Indian Tribes (together, the “Trustees”). The Letter appears to allege that NWCS may be a potentially liable party that allegedly contributed to the release of hazardous substances that have injured natural resources at the LDW Site. Damages to natural resources are in addition to clean-up costs. The Letter, versions of which NWCS believes were sent to all or a group of the PRPs for the LDW Site, also notified its recipients of their opportunity to participate in the Trustees’ development of an Assessment Plan and the performance of a Natural Resources Damages Assessment (“NRDA”) in accordance with the Assessment Plan for both the LDW Site and the east and west waterways of the Harbor Island site. NWCS timely responded with correspondence to the NOAA Office of General Counsel, in which it declined the invitation at that time. NWCS does not know how other PRPs responded to the Letter, and has not received any further communication from NOAA or the Trustees. The Trustees have not responded to NWCS’ letter and NWCS is not aware of any further action by the Trustees with respect to the Assessment Plan and NRDA. At this point, the Company is not able to determine the likelihood or amount of an assessment of natural resource damages against NWCS in connection with this matter . Los Angeles County, California Landfill Expansion Litigation A. Chiquita Canyon, LLC Lawsuit Against Los Angeles County  In October 2004, the Company’s subsidiary, Chiquita Canyon, LLC (“CCL”), then under prior ownership, filed an application (the “Application”) with the County of Los Angeles (the “County”) Department of Regional Planning (“DRP”) for a conditional use permit (the “CUP”) to authorize the continued operation and expansion of the Chiquita Canyon Landfill (the “Landfill”). The Landfill has operated since 1972, and as a regional landfill, accepted approximately three million tons of materials for disposal and beneficial use in 2016. The Application requested expansion of the existing waste footprint on CCL’s contiguous property, an increase in maximum elevation, creation of a new entrance and new support facilities, construction of a facility for the County or another third-party operator to host household hazardous waste collection events, designation of an area for mixed organics/composting, and other modifications. After many years of reviews and delays, upon the recommendation of County staff, the County’s Regional Planning Commission (the “Commission”) approved the Application on April 19, 2017, but imposed operating conditions, fees and exactions that substantially reduce the historical landfill operations and represent a large increase in aggregate taxes and fees. CCL objected to many of the requirements imposed by the Commission. Current estimates for new costs imposed on CCL under the CUP are in excess of $300,000 . CCL appealed the Commission’s decision to the County Board of Supervisors, but the appeal was not successful. At a subsequent hearing, on July 25, 2017, the Board of Supervisors approved the CUP. On October 20, 2017, CCL filed in the Superior Court of California, County of Los Angeles a verified petition for writ of mandate and complaint against the County and the County Board of Supervisors captioned Chiquita Canyon, LLC v. County of Los Angeles, No. BS171262 (Los Angeles Co. Super Ct.) (the “Complaint”). The Complaint challenges the terms of the CUP in 13 counts generally alleging that the County violated multiple California and federal statutes and California and federal constitutional protections. CCL seeks the following relief: (a) an injunction and writ of mandate against certain of the CUP’s operational restrictions, taxes and fees, (b) a declaration that the challenged conditions are unconstitutional and in violation of state and federal statutes, (c) reimbursement for any such illegal fees paid under protest, (d) damages, (e) an award of just compensation for a taking, (f) attorney fees, and (g) all other appropriate legal and equitable relief. On December 6, 2017, the County filed a demurrer to the Complaint arguing that the Complaint is legally insufficient to proceed. At an initial trial-setting hearing on February 8, 2018, the Superior Court suggested that the Complaint should be amended to separate the claims seeking a writ of mandamus against the County. CCL filed its First Amended Complaint on March 23, 2018. The County filed its demurrer and motion to strike challenging portions of the First Amended Complaint on April 25, 2018. CCL filed its combined opposition to the demurrer and motion to strike on July 3, 2018. The County filed a combined reply brief on July 10, 2018. The hearing on the demurrer took place on July 17, 2018. The Court sustained the demurrer and granted the motion to strike. The effect of the Court’s rulings is to bar CCL from proceeding with its challenges to 14 of the 29 CUP conditions at issue in the litigation, including 13 operational conditions and CCL’s challenge to the $11,600 B&T Fee discussed below. The Court set a trial date of June 18, 2019 for the remaining mandamus claims. The Court granted CCL leave to amend its Complaint if CCL chose to pay the $11,600 B&T fee to allow a challenge to the B&T fee to proceed under the Mitigation Fee Act. CCL paid the $11,600 B&T fee on August 10, 2018 and filed its Second Amended Complaint on August 16, 2018, reflecting that the B&T fee had been paid under protest and allowing the challenges to the B&T fee to go forward. On September 14, 2018, CCL appealed to the California Court of Appeal the Superior Court’s July 17, 2018 decision barring the challenge to 13 operational conditions. On October 5, 2018, the Court of Appeal decided to hear CCL’s appeal and issued an order to show cause, setting a briefing schedule and calendaring oral argument for January 9, 2019. CCL will vigorously prosecute the lawsuit. However, at this point, the Company is not able to determine the likelihood of any outcome in this matter. B. CEQA Lawsuit Against Los Angeles County Challenging Environmental Review for Landfill Expansion  A separate lawsuit involving CCL and the Landfill was filed on August 24, 2017 by community activists alleging that the environmental review underlying the CUP was inadequate under state law. The Val Verde Civic Association, Citizens for Chiquita Canyon Landfill Compliance, and the Santa Clarita Organization for Planning the Environment filed a petition for writ of mandate in the Superior Court of California, County of Los Angeles against the County, naming CCL as the real party in interest. The lawsuit seeks to overturn the County’s approval of the CUP for the expansion of the Landfill and the certification of the final Environmental Impact Report, arguing that the report violates the California Environmental Quality Act. Pursuant to Condition No. 6 of the CUP, which requires CCL to defend, indemnify, and hold harmless the County, its agents, officers, and employees from any claim or proceeding against the County brought by any third party to attack, set aside, void, or annul the CUP approval, CCL has agreed to reimburse the County for its legal costs associated with defense of the lawsuit. As the real party in interest, CCL has a right to notice and an opportunity to be heard in opposition to the petition for writ of mandate. The petitioners filed their Opening Brief with the court on September 27, 2018. CCL is scheduled to file its Opposition Brief with the court on November 28, 2018 and the petitioners are scheduled to file their Reply Brief on December 20, 2018. A trial date is scheduled for February 8, 2019. CCL intends to vigorously defend the lawsuit as the real party in interest. However, at this point, the Company is not able to determine the likelihood of any outcome in this matter. C. Solid Waste Management Fee Enforcement Order  On September 15, 2016, CCL received a letter from the County’s Department of Public Works (“DPW”), which alleged that from October 2011 to September 2014, CCL underpaid the County Solid Waste Management Fee in violation of the Los Angeles County Code. An invoice totaling more than $5,100 , which included certain fees and penalties, was attached to the letter, with 30-day payment terms. DPW argues that the penalty continues to accrue, and as of July 31, 2018 the penalties were calculated by DPW at $3,079 , for a total fee and penalty assessment of $5,515 . On September 29, 2016, CCL submitted an initial response to the DPW letter. CCL filed a protective administrative appeal on October 13, 2016. DPW responded on July 27, 2017, after the CUP was approved, rejecting CCL’s arguments and stating its intention to proceed with an Enforcement Order if the outstanding invoice was not paid. CCL responded on August 25, 2017, addressing each point raised by DPW and reiterated its position that no additional fees were due. On August 30, 2017, DPW issued an Enforcement Order seeking payment of the Solid Waste Management Fee and the administrative penalties that had allegedly accrued through March 2015, together totaling more than $5,100. CCL filed a timely administrative appeal of the order on September 28, 2017. CCL negotiated with County Counsel to set a briefing schedule, hearing date for the appeal, and selection of a neutral hearing officer. A prehearing order was entered on July 9, 2018 by the hearing officer and CCL and DPW proceeded to exchange briefs, exhibits, and written testimony of witnesses. A two-day evidentiary hearing on DPW’s Enforcement Order occurred on September 11-12, 2018. Post-hearing briefing is underway. It is uncertain when a decision will be issued. CCL has a right to challenge in State court any decision of the hearing officer that is not supported by the law or substantial evidence. At this point, the Company is not able to determine the likelihood of any outcome in this matter. D. December 11, 2017 Notice of Violation Regarding Certain CUP Conditions.  The County, through its DRP, issued a Notice of Violation, dated December 11, 2017 (the “NOV”), alleging that CCL violated certain conditions of the CUP, including Condition 79(B)(6) of the CUP by failing to pay an $11,600 Bridge & Thoroughfare Fee (“B&T Fee”) that was purportedly due on July 25, 2017. The alleged B&T fee was ostensibly to fund the construction of transportation infrastructure in the area of the Landfill. At the time the NOV was issued, CCL had already contested the legality of the B&T fee in the October 20, 2017 Complaint filed against the County in Los Angeles County Superior Court. On January 12, 2018, CCL filed an appeal of the alleged violations in the NOV. Subsequently, CCL filed additional legal arguments and exhibits contesting the NOV. On March 6, 2018, a DRP employee designated as hearing officer sustained the NOV, including the $11,600 B&T fee, and imposed an administrative penalty in the amount of $83 and a noncompliance fee of $0.75 . A written decision memorializing the hearing officer’s findings and order, dated July 10, 2018, was received by CCL on July 12, 2018. On April 13, 2018, CCL filed in the Superior Court of California, County of Los Angeles a Petition for Writ of Administrative Mandamus against the County seeking to overturn the decision sustaining the NOV, contending that the NOV and decision are not supported by the facts or law. On June 22, 2018, Chiquita filed a Motion for Stay seeking to halt enforcement of the B&T fee and penalty and the accrual of any further penalties pending the resolution of the Petition for Writ of Mandamus. The motion was heard and denied by the Court on July 17, 2018. As explained above, the Court granted CCL leave to pay the $11,600 B&T fee and to amend its Complaint to reflect the payment under protest, allowing the challenge to the B&T fee to proceed. CCL paid the B&T fee on August 10, 2018, and also paid on that date the administrative penalty of $83 and a noncompliance fee of $0.75 . As directed by the Court, CCL amended its Complaint in a Second Amended Complaint filed in the CUP action on August 16, 2018. The Court indicated that the NOV case would likely be tried in conjunction with the CUP case, set for June 18, 2019, and that the cases would be coordinated. At this point, the Company is not able to determine the likelihood of any outcome in this matter. Florida Default Judgment On January 5, 2017, a state court in Miami, Florida entered a $10,000 final judgment (“Judgment”) against the Company’s subsidiary, Progressive Waste Solutions of FL, Inc. (“Progressive”), which is now known as Waste Connections of Florida, Inc. The Judgment was the result of a default against Progressive for failure to respond to or otherwise defend itself against a complaint filed on July 21, 2015, prior to the closing of the Progressive Waste acquisition. The Company and Progressive learned of the Judgment on March 6, 2018. On March 20, 2018, Progressive filed a motion to set aside judgment and requested that the trial court (1) allow the case to proceed on the merits, (2) stay any efforts to execute or collect on the Judgment, and (3) dissolve any and all writs of garnishment. The trial judge denied the motion on April 10, 2018. Progressive continues to vigorously defend itself from the Judgment. On May 2, 2018, Progressive filed an appeal of the April 10, 2018 order and posted a civil supersedeas bond to stop all efforts to collect on the Judgment pending the outcome of its appeal. The appeal has been fully briefed and is scheduled for oral argument on December 4, 2018. At this time, the Company is unable to express an opinion on the likelihood of an unfavorable outcome to Progressive or express an opinion on the amount or range of potential loss in the event of an unfavorable outcome. As a result, the Company has not accrued any liability for the Judgment. Town of Colonie, New York Landfill Expansion Litigation On April 16, 2014, the Town of Colonie filed an application (the “Application”) with the New York State Department of Environmental Conservation (“DEC”) to modify the Town’s then-current Solid Waste Management Facility Permit and for other related permits to authorize the development and operation of Area 7 of the Town of Colonie Landfill (the “Landfill”), which is located in Albany County, New York. DEC issued the requested permits on April 5, 2018 (the “Permits”). The Company’s subsidiary, Capital Region Landfills, Inc. (“CRL”), has been the sole operator of the Landfill since September 2011 pursuant to an operating agreement between CRL and the Town. On May 7, 2018, the Town of Halfmoon, New York, and five of its residents, commenced an Article 78 special proceeding in the Supreme Court of the State of New York, Saratoga County, against DEC, the Town, CRL, and the Company (the “Halfmoon Proceeding”). On that same date, the Town of Waterford, New York, and eleven of its residents, also commenced an Article 78 special proceeding in the Supreme Court of the State of New York, Saratoga County, against the same respondents (the “Waterford Proceeding”). On June 15, 2018, the Waterford Petitioners served an Amended Verified Petition, removing the Company as a respondent. The Halfmoon Petitioners served an Amended Verified Petition on July 5, 2018, retaining all originally-named parties. The Company has moved to dismiss the Halfmoon Amended Verified Petition and that motion is fully submitted to the court. The Petitioners allege that, in granting the Permits, DEC failed to comply with the procedural and substantive requirements of New York’s Environmental Conservation Law and State Environmental Quality Review Act, and their implementing regulations. The Petitioners have asked the court to: annul the Permits and invalidate DEC’s Findings Statement, enjoin the Town and CRL from taking any action authorized by the Permits, require an issues conference and possibly an adjudicatory hearing before DEC can re-consider the Town’s permit application; remand all regulatory issues to a DEC Administrative Law Judge; and award costs and disbursements. The Waterford Petitioners have also requested reasonable attorneys’ fees. On July 13, 2018, the court granted a venue change motion filed by DEC, and ordered that the Halfmoon and Waterford Proceedings be transferred to the Supreme Court, Albany County. No return date has been established by the court, but Article 78 proceedings are intended to be resolved expeditiously, and generally without discovery. CRL’s opposition submissions, including its responsive pleadings, Memorandum of Law, and supporting Affidavits, were filed and served on or before July 25, 2018. On August 28, 2018, the Towns of Waterford and Halfmoon filed a motion seeking an order preliminarily enjoining during the pendency of the proceedings all activities relating to the expansion of the Landfill which are authorized by the Permits. On September 18, 2018, CRL and the Company filed and served Memoranda of Law in opposition to the preliminary injunction motion, with supporting Affidavits, and that motion is fully submitted to the court. CRL (and, if it remains a respondent, the Company), will vigorously oppose the Halfmoon and Waterford Proceedings. CRL believes that, in issuing the Permits, DEC followed the appropriate statutory and regulatory procedures and made a reasoned determination that is well-supported by the factual record. However, at this point, the Company is not able to determine the likelihood of any outcome in these proceedings.  

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2018
Subsequent Events [Abstract]
Subsequent Events	19. SUBSEQUENT EVENTS On October 29, 2018 , the Company announced that its Board of Directors increased its regular quarter cash dividend by $0.02 , from $0.14 to $0.16 per Company common share, and then declared a regular quarterly cash dividend of $0.16 per Company common share. The dividend will be paid on November 27, 2018 , to shareholders of record on the close of business on November 13, 2018 . 

Revenue (Policies)

Revenue (Policies)	9 Months Ended
	Sep. 30, 2018
Revenue [Abstract]
Revenue by Service Line	Revenue by Service Line Solid Waste Collection The Company’s solid waste collection business involves the collection of waste for transport to transfer stations, or directly to landfills or recycling centers. Solid waste collection services include both recurring and temporary customer relationships. The standard customer service agreements generally range from one to three years in duration, although some exclusive franchises are for significantly longer periods. The fees received for collection services are based primarily on the market, collection frequency, type of service, type and volume or weight of the waste collected, the distance to the disposal facility and the cost of disposal. In general, residential collection fees are billed monthly or quarterly in advance. Substantially all of the deferred revenue recognized as of June 30, 2018 was recognized as revenue during the three months ended September 30, 2018 when the service was performed. Commercial customers are typically billed on a monthly basis based on the nature of the services provided during the period. Revenue recognized under these agreements is variable in nature based on the number of residential homes or businesses serviced during the period, the frequency of collection and the volume of waste collected. In addition, certain contracts have annual price escalation clauses that are tied to changes in an underlying base index such as a consumer price index which are unknown at contract inception. Solid waste collection revenue from sources other than customer contracts primarily relates to lease revenue associated with compactors. Revenue from these leasing arrangements was not material and represented an insignificant amount of total revenue for each of the reported periods. Landfill and Transfer Station Revenue at landfills is primarily generated by charging tipping fees to third parties based on the volume disposed and the nature of the waste. In general, fees are variable in nature and revenue is recognized at the time the waste is disposed at the facility. Revenue at transfer stations is primarily generated by charging tipping or disposal fees. The fees charged to third parties are based primarily on the market, type and volume or weight of the waste accepted, the distance to the disposal facility and the cost of disposal. In general, fees are billed and revenue is recognized at the time the service is performed. Revenue recognized under these agreements is variable in nature based on the volume of waste accepted at the transfer facility. Solid Waste Recycling Solid waste recycling revenues are generated by offering residential, commercial, industrial and municipal customers recycling services for a variety of recyclable materials, including compost, cardboard, office paper, plastic containers, glass bottles and ferrous and aluminum metals. The Company owns recycling operations and sells collected recyclable materials to third parties for processing before resale. In certain instances, the Company issues recycling rebates to municipal or commercial customers, which can be based on the price it receives upon the sale of recycled commodities, a fixed contractual rate or other measures. The Company also receives rebates when it disposes of recycled commodities at third-party facilities. The fees received are based primarily on the market, type and volume or weight of the materials sold. In general, fees are billed and revenue is recognized at the time title is transferred. Revenue recognized under these agreements is variable in nature based on the volume of materials sold. In addition, the amount of revenue recognized is based on commodity prices at the time of sale, which are unknown at contract inception. E&P Waste Treatment, Recovery and Disposal E&P revenue is primarily generated through the treatment, recovery and disposal of non-hazardous exploration and production waste from vertical and horizontal drilling, hydraulic fracturing, production and clean-up activity, as well as other services including closed loop collection systems and the sale of recovered products. E&P activity varies across market areas that are tied to the natural resource basins in which the drilling activity occurs and reflects the regulatory environment, pricing and disposal alternatives available in any given market. Revenue recognized under these agreements is variable in nature based on the volume of waste accepted or processed during the period. Intermodal and Other Intermodal revenue is primarily generated through providing intermodal services for the rail haul movement of cargo and solid waste containers in the Pacific Northwest through a network of intermodal facilities. The fees received for intermodal services are based on negotiated rates and vary depending on volume commitments by the shipper and destination. In general, fees are billed and revenue is recognized upon delivery.
Revenue Recognition	Revenue Recognition Service obligations of a long-term nature, e.g., solid waste collection service contracts, are satisfied over time, and revenue is recognized based on the value provided to the customer during the period. The amount billed to the customer is based on variable elements such as the number of residential homes or businesses for which collection services are provided, the volume of waste collected, transported and disposed, and the nature of the waste accepted. The Company does not disclose the value of unsatisfied performance obligations for these contracts as its right to consideration corresponds directly to the value provided to the customer for services completed to date and all future variable consideration is allocated to wholly unsatisfied performance obligations. Additionally, certain elements of long-term customer contracts are unknown upon entering into the contract, including the amount that will be billed in accordance with annual price escalation clauses, fuel recovery fee programs and commodity prices. The amount to be billed is often tied to changes in an underlying base index such as a consumer price index or a fuel or commodity index, and revenue is recognized once the index is established for the period.
Accounts Receivable	Accounts Receivable Accounts receivable are recorded when billed or accrued and represent claims against third parties that will be settled in cash. The carrying value of the Company’s receivables, net of the allowance for doubtful accounts, represents their estimated net realizable value. The Company estimates its allowance for doubtful accounts based on historical collection trends, type of customer such as municipal or non-municipal, the age of outstanding receivables and existing economic conditions. If events or changes in circumstances indicate that specific receivable balances may be impaired, further consideration is given to the collectability of those balances and the allowance is adjusted accordingly. Past-due receivable balances are written off when the Company’s internal collection efforts have been unsuccessful in collecting the amount due.
Contract Acquisition Costs	Contract Acquisition Costs The incremental direct costs of obtaining a contract, which consist of sales incentives, are recognized as Other assets in the Company’s condensed consolidated balance sheet, and are amortized to Selling, general and administrative expense over the estimated life of the relevant customer relationship, which ranges from one to five years. The Company applied the standard’s practical expedient that permits an entity to recognize the incremental costs of obtaining a contract as an expense when incurred if the amortization period of the asset that the entity would have recognized is one year or less. As of September 30, 2018, the Company had $16,300 of deferred sales incentives. During the three and nine months ended September 30, 2018, the Company recorded amortization expense of $4,666 and $13,260 , respectively, for sales incentives costs

Revenue (Tables)

Revenue (Tables)	9 Months Ended
	Sep. 30, 2018
Revenue [Abstract]
Total Reported Revenues by Service Line	The following table disaggregates the Company’s revenues by service line for the periods indicated:   Three months ended September 30, Nine months ended September 30,  2018 2017 2018 2017  Commercial $ 369,543 $ 342,961 $ 1,080,261 $ 1,005,110  Residential 300,026 286,068 881,927 845,493  Industrial and construction roll off 202,130 186,315 573,877 530,219  Total collection 871,699 815,344 2,536,065 2,380,822  Landfill 285,945 261,706 790,056 744,352  Transfer 187,961 155,058 495,317 445,612  Recycling 23,371 43,864 69,559 131,445  E&P 68,049 57,797 189,071 147,662  Intermodal and other 34,261 38,221 105,588 107,418  Intercompany (190,176) (165,512) (524,447) (483,998)  Total $ 1,281,110 $ 1,206,478 $ 3,661,209 $ 3,473,313  

Landfill Accounting (Tables)

Landfill Accounting (Tables)	9 Months Ended
	Sep. 30, 2018
Landfill Accounting [Abstract]
Reconciliation of Final Capping, Closure and Post-Closure Liability Balance	The following is a reconciliation of the Company’s final capping, closure and post-closure liability balance from December 31, 2017 to September 30, 2018:   Final capping, closure and post-closure liability at December 31, 2017 $ 237,817  Adjustments to final capping, closure and post-closure liabilities (13,139)  Liabilities incurred 11,750  Accretion expense associated with landfill obligations 9,583  Closure payments (2,411)  Assumption of closure liabilities from acquisitions 4,408  Foreign currency translation adjustment (1,098)  Final capping, closure and post-closure liability at September 30, 2018 $ 246,910  

Acquisitions (Tables)

Acquisitions (Tables)	9 Months Ended
	Sep. 30, 2018
Acquisitions [Abstract]
Summary of Consideration Transferred to Acquire Businesses and Amounts of Identifiable Assets Acquired, Liabilities Assumed and Noncontrolling Interests	The following table summarizes the consideration transferred to acquire these businesses and the preliminary amounts of identifiable assets acquired and liabilities assumed at the acquisition dates for the acquisitions consummated in the nine months ended September 30, 2018 and 2017:   2018 Acquisitions 2017 Acquisitions Fair value of consideration transferred:  Cash $ 500,064 $ 394,002  Debt assumed 65,010 56,958  Notes issued to sellers - 13,460  Fair value of operations exchanged - 81,097  565,074 545,517  Recognized amounts of identifiable assets acquired and liabilities assumed associated with businesses acquired:  Accounts receivable 12,817 19,312  Prepaid expenses and other current assets 2,355 4,336  Property and equipment 346,275 167,065  Long-term franchise agreements and contracts 10,888 54,674  Customer lists 27,330 28,033  Indefinite-lived intangibles - 5,830  Other intangibles 31,183 27,261  Other assets 19 3,052  Accounts payable and accrued liabilities (3,982) (12,022)  Deferred revenue (4,169) (9,657)  Contingent consideration (11,669) (35)  Other long-term liabilities (15,532) (1,080)  Deferred income taxes (391) (50,283)  Total identifiable net assets 395,124 236,486  Goodwill $ 169,950 $ 309,031  

Assets Held for Sale (Tables)

Assets Held for Sale (Tables)	9 Months Ended
	Sep. 30, 2018
Assets Held for Sale [Abstract]
Assets and Liabilities Held for Sale	The Company’s assets and liabilities held for sale as of September 30, 2018 and December 31, 2017, were comprised of the following:   September 30, 2018 December 31, 2017 Current assets held for sale:  Cash and equivalents $ - $ 192  Accounts receivable 735 1,185  Other current assets 59 219  $ 794 $ 1,596 Long-term assets held for sale:  Property and equipment $ 413 $ 12,623  Goodwill 332 2  $ 745 $ 12,625 Current liabilities held for sale:  Accounts payable $ 157 $ 804  Accrued liabilities 22 215  Deferred revenue 749 1,136  $ 928 $ 2,155 

Intangible Assets, Net (Tables)

Intangible Assets, Net (Tables)	9 Months Ended
	Sep. 30, 2018
Intangible Assets, Net [Abstract]
Intangible Assets Exclusive of Goodwill	Intangible assets, exclusive of goodwill, consisted of the following at September 30, 2018:   Gross Carrying Amount Accumulated Amortization Accumulated Impairment Loss Net Carrying Amount Finite-lived intangible assets: Long-term franchise agreements and contracts $ 483,749 $ (150,691) $ - $ 333,058 Customer lists 429,801 (219,104) - 210,697 Permits and other 349,207 (46,120) - 303,087  1,262,757 (415,915) - 846,842 Indefinite-lived intangible assets: Solid waste collection and transportation permits 158,591 - - 158,591 Material recycling facility permits 42,283 - - 42,283 E&P facility permits 59,855 - (38,507) 21,348  260,729 - (38,507) 222,222 Intangible assets, exclusive of goodwill $ 1,523,486 $ (415,915) $ (38,507) $ 1,069,064   Intangible assets, exclusive of goodwill, consisted of the following at December 31, 2017:   Gross Carrying Amount Accumulated Amortization Accumulated Impairment Loss Net Carrying Amount Finite-lived intangible assets: Long-term franchise agreements and contracts $ 481,293 $ (123,591) $ - $ 357,702 Customer lists 405,683 (180,440) - 225,243 Permits and other 317,984 (35,715) - 282,269  1,204,960 (339,746) - 865,214 Indefinite-lived intangible assets: Solid waste collection and transportation permits 158,591 - - 158,591 Material recycling facility permits 42,283 - - 42,283 E&P facility permits 59,855 - (38,507) 21,348  260,729 - (38,507) 222,222 Intangible assets, exclusive of goodwill $ 1,465,689 $ (339,746) $ (38,507) $ 1,087,436  
Estimated Future Amortization Expense of Amortizable Intangible Assets	Estimated future amortization expense for the next five years relating to finite-lived intangible assets is as follows:   For the year ending December 31, 2018 $ 105,991  For the year ending December 31, 2019 $ 95,653  For the year ending December 31, 2020 $ 85,751  For the year ending December 31, 2021 $ 75,561  For the year ending December 31, 2022 $ 65,904 

Long-Term Debt (Tables)

Long-Term Debt (Tables)	9 Months Ended
	Sep. 30, 2018
Long-Term Debt [Abstract]
Long-Term Debt	The following table presents the Company’s long-term debt as of September 30, 2018 and December 31, 2017:   September 30, 2018 December 31, 2017  Revolver under Credit Agreement, bearing interest at 2.93 % (a) $ 169,950 $ 192,101  Term loan under Credit Agreement, bearing interest at 3.34 % (a) 1,637,500 1,637,500  2018 Senior Notes - 50,000  2019 Senior Notes 175,000 175,000  2021 Senior Notes 100,000 100,000  New 2021 Senior Notes 150,000 150,000  2022 Senior Notes 125,000 125,000  2023 Senior Notes 200,000 200,000  2024 Senior Notes 150,000 150,000  2025 Senior Notes 375,000 375,000  2026 Senior Notes 400,000 400,000  2027 Senior Notes 250,000 250,000  Tax-exempt bond, bearing interest at 1.61 % (a) 15,930 95,430  Notes payable to sellers and other third parties, bearing interest ranging from 2.75 % to 24.81 % (a) 14,950 26,290  3,763,330 3,926,321  Less – current portion (1,753) (11,659)  Less – debt issuance costs (14,368) (15,090)  $ 3,747,209 $ 3,899,572 ____________________ (a) Interest rates represent the interest rates incurred at September 30, 2018 .
Details of the Company's Credit Agreement	Details of the Credit Agreement are as follows:    September 30, 2018 December 31, 2017 Revolver under Credit Agreement  Available $ 1,252,021 $ 1,149,813  Letters of credit outstanding $ 140,529 $ 220,586  Total amount drawn, as follows: $ 169,950 $ 192,101  Amount drawn – Canadian prime rate loan $ - $ 16,739  Interest rate applicable – Canadian prime rate loan - 3.45%  Amount drawn – Canadian bankers’ acceptance $ 169,950 $ 175,362  Interest rate applicable – Canadian bankers’ acceptance 2.93% 2.64%  Commitment – rate applicable 0.12% 0.15%  Term loan under Credit Agreement  Amount drawn – U.S. based LIBOR loan $ 1,637,500 $ 1,637,500  Interest rate applicable – U.S. based LIBOR loan 3.34% 2.77% 

Segment Reporting (Tables)

Segment Reporting (Tables)	9 Months Ended
	Sep. 30, 2018
Segment Reporting [Abstract]
Summary of Financial Information Concerning Company's Reportable Segments	Summarized financial information concerning the Company’s reportable segments for the three and nine months ended September 30, 2018 and 2017, is shown in the following tables:  Three Months Ended September 30, 2018 Revenue Intercompany Revenue (b) Reported Revenue Segment EBITDA (c)  Southern $ 321,306 $ (38,266) $ 283,040 $ 70,159  Western 303,614 (32,596) 271,018 86,174  Eastern 353,844 (64,347) 289,497 83,721  Canada 211,682 (24,628) 187,054 68,819  Central 213,492 (28,221) 185,271 70,288  E&P 67,348 (2,118) 65,230 35,099  Corporate (a) - - - (8,286)  $ 1,471,286 $ (190,176) $ 1,281,110 $ 405,974   Three Months Ended September 30, 2017 Revenue Intercompany Revenue (b) Reported Revenue Segment EBITDA (c)  Southern $ 317,059 $ (36,531) $ 280,528 $ 63,171  Western 292,222 (30,345) 261,877 84,861  Eastern 292,124 (45,857) 246,267 74,018  Canada 224,166 (27,111) 197,055 74,369  Central 190,210 (23,850) 166,360 64,607  E&P 56,209 (1,818) 54,391 27,881  Corporate (a) - - - (5,751)  $ 1,371,990 $ (165,512) $ 1,206,478 $ 383,156   Nine Months Ended September 30, 2018 Revenue Intercompany Revenue (b) Reported Revenue Segment EBITDA (c)  Southern $ 951,313 $ (111,824) $ 839,489 $ 207,853  Western 874,464 (94,584) 779,880 240,006  Eastern 966,571 (164,253) 802,318 225,950  Canada 615,157 (71,290) 543,867 195,390  Central 591,417 (77,337) 514,080 191,840  E&P 186,734 (5,159) 181,575 95,009  Corporate (a) - - - (14,368)  $ 4,185,656 $ (524,447) $ 3,661,209 $ 1,141,680   Nine Months Ended September 30, 2017 Revenue Intercompany Revenue (b) Reported Revenue Segment EBITDA (c)  Southern $ 957,506 $ (111,472) $ 846,034 $ 199,280  Western 845,176 (90,217) 754,959 247,475  Eastern 851,880 (133,578) 718,302 209,315  Canada 621,995 (75,846) 546,149 200,283  Central 536,803 (66,716) 470,087 177,975  E&P 143,951 (6,169) 137,782 63,518  Corporate (a) - - - (32,535)  $ 3,957,311 $ (483,998) $ 3,473,313 $ 1,065,311 ____________________ (a) Corporate functions include accounting, legal, tax, treasury, information technology, risk management, human resources, training and other administrative functions. Amounts reflected are net of allocations to the six operating segments. (b) Intercompany revenues reflect each segment’s total intercompany sales, including intercompany sales within a segment and between segments. Transactions within and between segments are generally made on a basis intended to reflect the market value of the service. (c) For those items included in the determination of segment EBITDA, the accounting policies of the segments are the same as those described in the Company’s most recent Annual Report on Form 10-K.
Total Assets for Reportable Segments	Total assets for each of the Company’s reportable segments at September 30, 2018 and December 31, 2017, were as follows:    September 30, 2018 December 31, 2017  Southern $ 2,778,123 $ 2,718,296  Western 1,583,561 1,573,955  Eastern 2,348,438 2,024,527  Canada 2,562,659 2,677,557  Central 1,452,607 1,297,118  E&P 974,049 981,980  Corporate 492,629 741,248  Total Assets $ 12,192,066 $ 12,014,681 
Changes in Goodwill by Reportable Segment	The following tables show changes in goodwill during the nine months ended September 30, 2018 and 2017, by reportable segment:     Southern Western Eastern Canada Central E&P Total  Balance as of December 31, 2017 $ 1,436,320 $ 397,508 $ 804,133 $ 1,575,538 $ 468,275 $ - $ 4,681,774  Goodwill acquired 4,800 666 122,136 151 42,197 - 169,950  Goodwill adjustment for assets held for sale 10,194 - - - - - 10,194  Impact of changes in foreign currency - - - (48,622) - - (48,622)  Balance as of September 30, 2018 $ 1,451,314 $ 398,174 $ 926,269 $ 1,527,067 $ 510,472 $ - $ 4,813,296     Southern Western Eastern Canada Central E&P Total  Balance as of December 31, 2016 $ 1,470,023 $ 376,537 $ 533,160 $ 1,465,274 $ 467,924 $ 77,343 $ 4,390,261  Goodwill acquired 7,484 20,906 272,501 7,127 1,013 - 309,031  Goodwill divested (31,543) - (4,276) - (667) - (36,486)  Impairment loss - - - - - (77,343) (77,343)  Goodwill adjustment for assets sold 2,205 - 321 - - - 2,526  Goodwill adjustment for assets held for sale (11,080) - - - - - (11,080)  Impact of changes in foreign currency - - - 111,439 - - 111,439  Balance as of September 30, 2017 $ 1,437,089 $ 397,443 $ 801,706 $ 1,583,840 $ 468,270 $ - $ 4,688,348  
Reconciliation of Primary Measure of Segment Profitability to Income Before Income Tax Provision	A reconciliation of the Company’s primary measure of segment profitability (segment EBITDA) to Income before income tax provision in the Condensed Consolidated Statements of Net Income is as follows:   Three months ended September 30, Nine months ended September 30,  2018 2017 2018 2017  Southern segment EBITDA $ 70,159 $ 63,171 $ 207,853 $ 199,280  Western segment EBITDA 86,174 84,861 240,006 247,475  Eastern segment EBITDA 83,721 74,018 225,950 209,315  Canada segment EBITDA 68,819 74,369 195,390 200,283  Central segment EBITDA 70,288 64,607 191,840 177,975  E&P segment EBITDA 35,099 27,881 95,009 63,518  Subtotal reportable segments 414,260 388,907 1,156,048 1,097,846  Unallocated corporate overhead (8,286) (5,751) (14,368) (32,535)  Depreciation (148,232) (136,941) (423,866) (395,008)  Amortization of intangibles (26,871) (26,613) (79,444) (76,886)  Impairments and other operating items 1,998 (832) (6,106) (141,333)  Interest expense (32,078) (32,471) (96,874) (92,763)  Interest income 1,467 1,656 3,677 3,131  Other income, net 732 1,709 2,376 3,561  Foreign currency transaction loss (132) (1,864) (323) (3,502)  Income before income tax provision $ 202,858 $ 187,800 $ 541,120 $ 362,511  

Derivative Financial Instrume_2

Derivative Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2018
Fair Value of Derivative Instrument Designated as Cash Flow Hedges	 The fair values of derivative instruments designated as cash flow hedges as of September 30, 2018, were as follows:  Derivatives Designated as Cash Asset Derivatives Liability Derivatives Flow Hedges Balance Sheet Location Fair Value Balance Sheet Location Fair Value  Interest rate swaps Prepaid expenses and other current assets (a) $ 11,380 Other long-term liabilities $ -  Other assets, net 25,834   Fuel hedges Prepaid expenses and other current assets (b) 2,189  Total derivatives designated as cash flow hedges $ 39,403 $ - ____________________ (a) Represents the estimated amount of the existing unrealized gains on interest rate swaps as of September 30, 2018 (based on the interest rate yield curve at that date), included in AOCIL expected to be reclassified into pre-tax earnings within the next 12 months. The actual amounts reclassified into earnings are dependent on future movements in interest rates. (b) Represents the estimated amount of the existing unrealized gains on the fuel hedge as of September 30, 2018 (based on the forward DOE diesel fuel index curve at that date), included in AOCIL expected to be reclassified into pre-tax earnings within the next 12 months. The actual amounts reclassified into earnings are dependent on future movements in diesel fuel prices.  The fair values of derivative instruments designated as cash flow hedges as of December 31, 2017, were as follows:  Derivatives Designated as Cash Asset Derivatives Liability Derivatives Flow Hedges Balance Sheet Location Fair Value Balance Sheet Location Fair Value  Interest rate swaps Prepaid expenses and other current assets $ 5,193 Accrued liabilities $ (903)  Other assets, net 15,182 Other long-term liabilities (493)   Fuel hedges Prepaid expenses and other current assets 3,880  Total derivatives designated as cash flow hedges $ 24,255 $ (1,396)  
Impact of Cash Flow Hedges on Results of Operations, Comprehensive Income (Loss) and Accumulated Other Comprehensive Income (Loss)	The following table summarizes the impact of the Company’s cash flow hedges on the results of operations, comprehensive income (loss) and AOCIL for the three and nine months ended September 30, 2018 and 2017:  Derivatives Designated as Cash Flow Hedges Amount of Gain or (Loss) Recognized as AOCIL on Derivatives, Net of Tax (Effective Portion) (a) Statement of Net Income Classification Amount of (Gain) or Loss Reclassified from AOCIL into Earnings, Net of Tax (Effective Portion) (b),(c)  Three Months Ended September 30, Three Months Ended September 30,  2018 2017 2018 2017  Interest rate swaps $ 634 $ (361) Interest expense $ 3,145 $ 376  Fuel hedges 222 1,680 Cost of operations (1,359) 487  Total $ 856 $ 1,319 $ 1,786 $ 863   Derivatives Designated as Cash Flow Hedges Amount of Gain or (Loss) Recognized as AOCIL on Derivatives, Net of Tax (Effective Portion) (a) Statement of Net Income Classification Amount of (Gain) or Loss Reclassified from AOCIL into Earnings, Net of Tax (Effective Portion) (b),(c)  Nine Months Ended September30, Nine Months Ended September 30,  2018 2017 2018 2017  Interest rate swaps $ 11,634 $ 224 Interest expense $ 1,769 $ 1,729  Fuel hedges 2,226 (1,030) Cost of operations (3,490) 1,704  Total $ 13,860 $ (806) $ (1,721) $ 3,433 ___________________ (a) In accordance with the derivatives and hedging guidance, the effective portions of the changes in fair values of interest rate swaps and fuel hedges have been recorded in equity as a component of AOCIL. As the critical terms of the interest rate swaps match the underlying debt being hedged, no ineffectiveness is recognized on these swaps and, therefore, all unrealized changes in fair value are recorded in AOCIL. Because changes in the actual price of diesel fuel and changes in the DOE index price do not offset exactly each reporting period, the Company assesses whether the fuel hedges are highly effective using the cumulative dollar offset approach. (b) Amounts reclassified from AOCIL into earnings related to realized gains and losses on interest rate swaps are recognized when interest payments or receipts occur related to the swap contracts, which correspond to when interest payments are made on the Company’s hedged debt. (c) Amounts reclassified from AOCIL into earnings related to realized gains and losses on the fuel hedges are recognized when settlement payments or receipts occur related to the hedge contracts, which correspond to when the underlying fuel is consumed.
Interest Rate Swap [Member]
Company's Derivative Instruments	At September 30, 2018, the Company’s derivative instruments included 16 interest rate swap agreements as follows:   Date Entered Notional Amount Fixed Interest Rate Paid* Variable Interest Rate Received Effective Date Expiration Date  April 2014 $ 100,000 1.800% 1-month LIBOR July 2014 July 2019  May 2014 $ 50,000 2.344% 1-month LIBOR October 2015 October 2020  May 2014 $ 25,000 2.326% 1-month LIBOR October 2015 October 2020  May 2014 $ 50,000 2.350% 1-month LIBOR October 2015 October 2020  May 2014 $ 50,000 2.350% 1-month LIBOR October 2015 October 2020  April 2016 $ 100,000 1.000% 1-month LIBOR February 2017 February 2020  June 2016 $ 75,000 0.850% 1-month LIBOR February 2017 February 2020  June 2016 $ 150,000 0.950% 1-month LIBOR January 2018 January 2021  June 2016 $ 150,000 0.950% 1-month LIBOR January 2018 January 2021  July 2016 $ 50,000 0.900% 1-month LIBOR January 2018 January 2021  July 2016 $ 50,000 0.890% 1-month LIBOR January 2018 January 2021  August 2017 $ 100,000 1.900% 1-month LIBOR July 2019 July 2022  August 2017 $ 200,000 2.200% 1-month LIBOR October 2020 October 2025  August 2017 $ 150,000 1.950% 1-month LIBOR February 2020 February 2023  June 2018 $ 200,000 2.925% 1-month LIBOR October 2020 October 2025  June 2018 $ 200,000 2.925% 1-month LIBOR October 2020 October 2025 ____________________ * Plus applicable margin.
Fuel [Member] | Commodity Contract [Member]
Company's Derivative Instruments	At September 30, 2018, the Company’s derivative instruments included one fuel hedge agreement as follows:  Date Entered Notional Amount (in gallons per month) Diesel Rate Paid Fixed (per gallon) Diesel Rate Received Variable Effective Date Expiration Date  July 2016 1,000,000 $2.6345 DOE Diesel Fuel Index* January 2018 December 2018 ____________________ * If the national U.S. on-highway average price for a gallon of diesel fuel (“average price”), as published by the U.S. Department of Energy (“DOE”), exceeds the contract price per gallon, the Company receives the difference between the average price and the contract price (multiplied by the notional number of gallons) from the counterparty. If the average price is less than the contract price per gallon, the Company pays the difference to the counterparty. 

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2018
Fair Value [Abstract]
Carrying Values and Fair Values of Debt Instruments	The carrying values and fair values of the Company’s debt instruments where the carrying values do not approximate their fair values as of September 30, 2018 and December 31, 2017, are as follows:   Carrying Value at Fair Value* at  September 30, 2018 December 31, 2017 September 30, 2018 December 31, 2017  2018 Senior Notes $ - $ 50,000 $ - $ 50,223  2019 Senior Notes $ 175,000 $ 175,000 $ 178,150 $ 182,547  2021 Senior Notes $ 100,000 $ 100,000 $ 101,780 $ 104,985  New 2021 Senior Notes $ 150,000 $ 150,000 $ 144,299 $ 146,855  2022 Senior Notes $ 125,000 $ 125,000 $ 121,062 $ 124,532  2023 Senior Notes $ 200,000 $ 200,000 $ 188,988 $ 194,660  2024 Senior Notes $ 150,000 $ 150,000 $ 143,651 $ 149,133  2025 Senior Notes $ 375,000 $ 375,000 $ 358,141 $ 375,311  2026 Senior Notes $ 400,000 $ 400,000 $ 369,921 $ 388,760  2027 Senior Notes $ 250,000 $ 250,000 $ 236,409 $ 250,029 ______________________ * Senior Notes are classified as Level 2 within the fair value hierarchy. Fair value is based on quotes of bonds with similar ratings in similar industries.

Net Income Per Share Informat_2

Net Income Per Share Information (Tables)	9 Months Ended
	Sep. 30, 2018
Net Income Per Share Information [Abstract]
Basic and Diluted Net Income Per Common Share	The following table sets forth the calculation of the numerator and denominator used in the computation of basic and diluted net income per common share attributable to the Company’s shareholders for the three and nine months ended September 30, 2018 and 2017:   Three months ended September 30, Nine months ended September 30,  2018 2017 2018 2017 Numerator:  Net income attributable to Waste Connections for basic and diluted earnings per share $ 150,843 $ 123,227 $ 414,393 $ 261,732  Denominator:  Basic shares outstanding 263,628,838 263,443,064 263,657,274 263,298,839  Dilutive effect of equity-based awards 765,919 856,408 719,046 810,544  Diluted shares outstanding 264,394,757 264,299,472 264,376,320 264,109,383  

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2018
Fair Value [Abstract]
Assets and Liabilities Measured at Fair Value on Recurring Basis	The Company’s assets and liabilities measured at fair value on a recurring basis at September 30, 2018 and December 31, 2017, were as follows:   Fair Value Measurement at September 30, 2018 Using  Total Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3)  Interest rate swap derivative instruments – net asset position $ 37,214 $ - $ 37,214 $ -  Fuel hedge derivative instrument – net asset position $ 2,189 $ - $ - $ 2,189  Restricted cash and investments $ 126,221 $ - $ 126,221 $ -  Contingent consideration $ (55,024) $ - $ - $ (55,024)    Fair Value Measurement at December 31, 2017 Using  Total Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3)  Interest rate swap derivative instruments – net asset position $ 18,979 $ - $ 18,979 $ -  Fuel hedge derivative instrument – net asset position $ 3,880 $ - $ - $ 3,880  Restricted cash and investments $ 165,592 $ - $ 165,592 $ -  Contingent consideration $ (47,285) $ - $ - $ (47,285) 
Change in Fair Value for Level 3 Derivatives	The following table summarizes the changes in the fair value for Level 3 derivatives for the nine months ended September 30, 2018 and 2017:    Nine Months Ended September 30,  2018 2017  Beginning balance $ 3,880 $ (264)  Realized (gains) losses included in earnings (4,647) 2,765  Unrealized gains (losses) included in AOCIL 2,956 (1,672)  Ending balance $ 2,189 $ 829  
Fair Value for Level 3 Liabilities	The following table summarizes the changes in the fair value for Level 3 liabilities related to contingent consideration for the nine months ended September 30, 2018 and 2017:   Nine Months Ended September 30,  2018 2017  Beginning balance $ 47,285 $ 51,826  Contingent consideration recorded at acquisition date 11,669 35  Payment of contingent consideration recorded at acquisition date (5,459) (5,840)  Payment of contingent consideration recorded in earnings (11) -  Adjustments to contingent consideration 349 17,754  Reclass earned contingent consideration to accrued liabilities - (20,464)  Interest accretion expense 1,308 1,381  Foreign currency translation adjustment (117) 263  Ending balance $ 55,024 $ 44,955  

Other Comprehensive Income (L_2

Other Comprehensive Income (Loss) (Tables)	9 Months Ended
	Sep. 30, 2018
Other Comprehensive Income (Loss) [Abstract]
Components of Other Comprehensive Income (Loss)	The components of other comprehensive income (loss) and related tax effects for the three and nine months ended September 30, 2018 and 2017 are as follows:   Three months ended September 30, 2018  Gross Tax effect Net of tax  Interest rate swap amounts reclassified into interest expense $ 4,279 $ (1,134) $ 3,145  Fuel hedge amounts reclassified into cost of operations (1,810) 451 (1,359)  Changes in fair value of interest rate swaps 863 (229) 634  Changes in fair value of fuel hedge 295 (73) 222  Foreign currency translation adjustment 35,455 - 35,455  $ 39,082 $ (985) $ 38,097     Three months ended September 30, 2017  Gross Tax effect Net of tax  Interest rate swap amounts reclassified into interest expense $ 511 $ (135) $ 376  Fuel hedge amounts reclassified into cost of operations 789 (302) 487  Changes in fair value of interest rate swaps 2,181 (2,542) (361)  Changes in fair value of fuel hedges 2,717 (1,037) 1,680  Foreign currency translation adjustment 84,500 - 84,500  $ 90,698 $ (4,016) $ 86,682     Nine months ended September 30, 2018  Gross Tax effect Net of tax  Interest rate swap amounts reclassified into interest expense $ 2,407 $ (638) $ 1,769  Fuel hedge amounts reclassified into cost of operations (4,647) 1,157 (3,490)  Changes in fair value of interest rate swaps 15,828 (4,194) 11,634  Changes in fair value of fuel hedge 2,956 (730) 2,226  Foreign currency translation adjustment (67,349) - (67,349)  $ (50,805) $ (4,405) $ (55,210)     Nine months ended September 30, 2017  Gross Tax effect Net of tax  Interest rate swap amounts reclassified into interest expense $ 2,352 $ (623) $ 1,729  Fuel hedge amounts reclassified into cost of operations 2,765 (1,061) 1,704  Changes in fair value of interest rate swaps 305 (81) 224  Changes in fair value of fuel hedges (1,672) 642 (1,030)  Foreign currency translation adjustment 155,153 - 155,153  $ 158,903 $ (1,123) $ 157,780  
Amounts Included in Accumulated Other Comprehensive Income (Loss)	A rollforward of the amounts included in AOCIL, net of taxes, for the nine months ended September 30, 2018 and 2017, is as follows:   Fuel Hedges Interest Rate Swaps Foreign Currency Translation Adjustment Accumulated Other Comprehensive Income (Loss)  Balance at December 31, 2017 $ 2,907 $ 13,951 $ 91,555 $ 108,413  Amounts reclassified into earnings (3,490) 1,769 - (1,721)  Changes in fair value 2,226 11,634 - 13,860  Foreign currency translation adjustment - - (67,349) (67,349)  Balance at September 30, 2018 $ 1,643 $ 27,354 $ 24,206 $ 53,203     Fuel Hedges Interest Rate Swaps Foreign Currency Translation Adjustment Accumulated Other Comprehensive Income (Loss)  Balance at December 31, 2016 $ (164) $ 8,094 $ (50,931) $ (43,001)  Amounts reclassified into earnings 1,704 1,729 - 3,433  Changes in fair value (1,030) 224 - (806)  Foreign currency translation adjustment - - 155,153 155,153  Balance at September 30, 2017 $ 510 $ 10,047 $ 104,222 $ 114,779 

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2018
Restricted Stock Units (RSUs) [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Summary of Activity Related to Restricted Stock Units	A summary of activity related to restricted share units (“RSUs”) during the nine-month period ended September 30, 2018, is presented below:   Unvested Shares  Outstanding at December 31, 2017 1,042,014  Granted 496,217  Forfeited (53,063)  Vested and issued (480,577)  Vested and deferred (3,653)  Outstanding at September 30, 2018 1,000,938  
Performance Shares [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Summary of Performance-Based Restricted Share Units Activity and Related Information	A summary of activity related to performance-based restricted share units (“PSUs”) during the nine-month period ended September 30, 2018, is presented below:   Unvested Shares  Outstanding at December 31, 2017 514,461  Granted 178,377  Forfeited (2,071)  Vested and issued (154,181)  Outstanding at September 30, 2018 536,586  
Deferred Share Units [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Summary of Activity Related to Restricted Stock Units	A summary of activity related to deferred share units (“DSUs”) during the nine-month period ended September 30, 2018, is presented below:   Vested Shares  Outstanding at December 31, 2017 13,138  Granted 4,038  Outstanding at September 30, 2018 17,176  
Progressive Waste Solutions Ltd. [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Summary of Stock Option Activity and Related Information	A summary of activity related to Progressive Waste share based options during the nine-month period ended September 30, 2018, is presented below:   Outstanding at December 31, 2017 236,616  Cash settled (71,460)  Outstanding at September 30, 2018 165,156 
Progressive Waste Solutions Ltd. [Member] | Restricted Stock Units (RSUs) [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Summary of Activity Related to Restricted Stock Units	A summary of activity related to Progressive Waste RSUs during the nine-month period ended September 30, 2018, is presented below:   Outstanding at December 31, 2017 158,510  Cash settled (27,059)  Forfeited (2,435)  Outstanding at September 30, 2018 129,016 
Summary of Vesting Activity Related to RSUs	A summary of vesting activity related to Progressive Waste RSUs during the nine-month period ended September 30, 2018, is presented below:   Vested at December 31, 2017 138,054  Vested over remaining service period 14,695  Cash settled (27,059)  Forfeited (2,435)  Vested at September 30, 2018 123,255 
Progressive Waste Solutions Ltd. [Member] | Performance Shares [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Summary of Performance-Based Restricted Share Units Activity and Related Information	A summary of activity related to Progressive Waste PSUs during the nine-month period ended September 30, 2018, is presented below:   Outstanding at December 31, 2017 55,602  Cash settled, net of notional dividend (27,033)  Forfeited (1,909)  Outstanding at September 30, 2018 26,660 
Summary of Vesting Activity Related to PSUs	A summary of vesting activity related to Progressive Waste PSUs during the nine-month period ended September 30, 2018, is presented below:   Vested at December 31, 2017 28,407  Vested over remaining service period 25,417  Cash settled, net of notional dividend (27,033)  Forfeited (1,909)  Vested at September 30, 2018 24,882 

New Accounting Standards (Narra

New Accounting Standards (Narrative) (Details) - USD ($) $ in Thousands	Jan. 01, 2018	Sep. 30, 2018	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
New Accounting Standards [Abstract]
Sales incentives					$ 16,000
Capitalized contract costs	$ 16,296	$ 16,300	$ 16,300
Capitalized Contract Cost, Amortization		4,666	13,260
Change in net cash provided by used in investing activities			39,494	$ 3,544
Cumulative effect adjustment from adoption of new accounting pronouncement	13,243	13,243	13,243
Deferred tax liability	4,058	$ 741,300	$ 741,300		690,767
New accounting standards, effect of change in revenue	$ 1,005
Provisional Transition Tax obligation					$ 1,000

Revenue (Narrative) (Details)

Revenue (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018	Jan. 01, 2018
Capitalized contract costs	$ 16,300	$ 16,300	$ 16,296
Capitalized contract costs amortization	$ 4,666	$ 13,260
Maximum [Member]
Standard customer service agreement period		3 years
Estimated life of relevant customer relationship		5 years
Minimum [Member]
Standard customer service agreement period		1 year
Estimated life of relevant customer relationship		1 year

Revenue (Total Reported Revenue

Revenue (Total Reported Revenues by Service Line) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenue from External Customer [Line Items]
Revenues	$ 1,281,110	$ 1,206,478	$ 3,661,209	$ 3,473,313
Collection [Member]
Revenue from External Customer [Line Items]
Revenues	871,699	815,344	2,536,065	2,380,822
Collection [Member] | Commercial [Member]
Revenue from External Customer [Line Items]
Revenues	369,543	342,961	1,080,261	1,005,110
Collection [Member] | Residential [Member]
Revenue from External Customer [Line Items]
Revenues	300,026	286,068	881,927	845,493
Collection [Member] | Industrial and Construction Roll Off [Member]
Revenue from External Customer [Line Items]
Revenues	202,130	186,315	573,877	530,219
Landfills [Member]
Revenue from External Customer [Line Items]
Revenues	285,945	261,706	790,056	744,352
Transfer [Member]
Revenue from External Customer [Line Items]
Revenues	187,961	155,058	495,317	445,612
Recycling [Member]
Revenue from External Customer [Line Items]
Revenues	23,371	43,864	69,559	131,445
E&P [Member]
Revenue from External Customer [Line Items]
Revenues	68,049	57,797	189,071	147,662
Intermodal and Other [Member]
Revenue from External Customer [Line Items]
Revenues	34,261	38,221	105,588	107,418
Intercompany Revenue [Member]
Revenue from External Customer [Line Items]
Revenues	$ (190,176)	$ (165,512)	$ (524,447)	$ (483,998)

Landfill Accounting (Narrative)

Landfill Accounting (Narrative) (Details) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2018USD ($)site$ / T	Sep. 30, 2017USD ($)$ / T	Dec. 31, 2017USD ($)
Landfill Accounting [Line Items]
Number of landfills owned and operated by company | site	81
Number of landfills operated, not owned, under life-of-site operating agreements | site	8
Number of landfills operated under limited-term operating agreements | site	4
Property and equipment, net	$ 5,069,767		$ 4,820,934
Average remaining landfill life based on permitted capacity and projected annual disposal volumes	26 years
Number of owned landfills the company is seeking to expand | site	11
Number of landfills operated under life-of-site operating agreements that the company is seeking to expand | site	3
Average remaining landfill life based on permitted capacity, projected annual disposal volumes and probable expansion capacity	30 years
Life of Company's owned landfills and landfills operated under life-of-site operating agreements min range	1 year
Life of Company's owned landfills and landfills operated under life of site operating agreements max range	158 years
Landfill depletion expense	$ 153,010	$ 147,071
Average rate per ton consumed related to landfill depletion at owned landfills and landfills operated under life-of-site agreements | $ / T	4.58	4.55
Inflation rate for purposes of computing layers for final capping, closure and post-closure obligations	2.50%		2.50%
Accretion expense associated with landfill obligations	$ 9,583	$ 8,757
Average rate per ton consumed related to final capping, closure and post-closure landfill accretion expense | $ / T	0.29	0.27
Restricted asset balance for purposes of securing our performance of future final capping, closure and post-closure obligations	$ 44,760		$ 43,684
Restricted investments	12,639		$ 12,406
Liabilities incurred	11,750
Landfill [Member]
Landfill Accounting [Line Items]
Property and equipment, net	$ 2,868,628
Fair value discount rate	4.75%		4.75%

Landfill Accounting (Reconcilia

Landfill Accounting (Reconciliation of Final Capping, Closure and Post-Closure Liability Balance) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Landfill Accounting [Abstract]
Final capping, closure and post-closure liability at the beginning of the period	$ 237,817
Adjustments to final capping, closure and post-closure liabilities	(13,139)
Liabilities incurred	11,750
Accretion expense associated with landfill obligations	9,583	$ 8,757
Closure payments	(2,411)
Assumption of closure liabilities from acquisitions	4,408
Foreign currency translation adjustment	(1,098)
Final capping, closure and post-closure liability at the end of the period	$ 246,910

Acquisitions (Narrative) (Detai

Acquisitions (Narrative) (Detail) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)entity	Sep. 30, 2017USD ($)entity	Sep. 30, 2018USD ($)entity	Dec. 31, 2016USD ($)customer	Jan. 31, 2017territory
Business Acquisition [Line Items]
Acquisition-related costs			$ 4,907	$ 4,418
Number of individual businesses acquired that are not specifically described | entity				11
Number of immaterial businesses acquired in period | entity			15
Revenues	$ 1,281,110	$ 1,206,478	$ 3,661,209	$ 3,473,313
Goodwill expected to be deductible for tax purposes	169,559	51,518	169,559	51,518	$ 169,559
Trade receivables acquired in business combination gross contractual amount	14,015	20,025	14,015	20,025	14,015
Trade receivables acquired in business combination expected to be uncollectible amount	1,198	$ 713	$ 1,198	$ 713	$ 1,198
Fair value of acquired working capital is provisional | entity					5
Groot Industries, Inc. [Member]
Business Acquisition [Line Items]
Revenues						$ 200,000
Groot Industries, Inc. [Member]
Business Acquisition [Line Items]
Number of customers served by company acquired | customer						300,000
Number of collection operations acquired | territory							7
Number of transfer stations acquired | territory							6
Number of recycling facilities acquired | territory							1
One Acquisition [Member]
Business Acquisition [Line Items]
Contingent consideration payable period			3 years
Fair value discount rate			2.70%
Contingent consideration	11,593		$ 11,593		$ 11,593
One Acquisition [Member] | Maximum [Member]
Business Acquisition [Line Items]
Contingent consideration	$ 12,582		$ 12,582		$ 12,582

Acquisitions (Summary of Consid

Acquisitions (Summary of Consideration Transferred to Acquire Businesses and Amounts of Identifiable Assets Acquired, Liabilities Assumed and Noncontrolling Interests) (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Fair value of consideration transferred:
Cash	$ 500,064	$ 394,002
Notes issued to sellers		13,460
Fair value of operations exchanged		81,097
Consideration transferred	565,074	545,517
Recognized amounts of identifiable assets acquired and liabilities assumed associated with businesses acquired:
Accounts receivable	12,817	19,312
Prepaid expenses and other current assets	2,355	4,336
Property and equipment	346,275	167,065
Indefinite-lived intangibles		5,830
Other assets	19	3,052
Deferred revenue	(4,169)	(9,657)
Other long-term liabilities	(15,532)	(1,080)
Deferred income taxes	(391)	(50,283)
Total identifiable net assets	395,124	236,486
Goodwill	169,950	309,031
Accounts Payable and Accrued Liabilities [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed associated with businesses acquired:
Accounts payable and accrued liabilities	(3,982)	(12,022)
Debt [Member]
Fair value of consideration transferred:
Liabilities incurred	65,010	56,958
Contingent Consideration [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed associated with businesses acquired:
Other long-term liabilities	(11,669)	(35)
Contracts [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed associated with businesses acquired:
Intangibles	10,888	54,674
Customer Lists [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed associated with businesses acquired:
Intangibles	27,330	28,033
Other Intangibles [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed associated with businesses acquired:
Intangibles	$ 31,183	$ 27,261

Assets Held for Sale (Narrative

Assets Held for Sale (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Assets Held for Sale [Abstract]
Cash consideration received for divestitures	$ 1,250
Loss recognized on assets held for sale		$ 4,466

Assets Held for Sale (Assets an

Assets Held for Sale (Assets and Liabilities Held for Sale) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Current assets held for sale:
Cash and equivalents		$ 192
Accounts receivable	$ 735	1,185
Other current assets	59	219
Current assets held for sale	794	1,596
Long-term assets held for sale:
Property and equipment	413	12,623
Goodwill	332	2
Long-term assets held for sale	745	12,625
Current liabilities held for sale:
Accounts payable	157	804
Accrued liabilities	22	215
Deferred revenue	749	1,136
Current liabilities held for sale	$ 928	$ 2,155

Intangible Assets, Net (Narrati

Intangible Assets, Net (Narrative) (Detail)	9 Months Ended
	Sep. 30, 2018
Long-term Franchise Agreements and Contracts [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted average amortization period of acquired intangible assets	16 years 3 months 18 days
Customer Lists [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted average amortization period of acquired intangible assets	10 years
Permits and Other [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted average amortization period of acquired intangible assets	40 years

Intangible Assets, Net (Intangi

Intangible Assets, Net (Intangible Assets Exclusive of Goodwill) (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross carrying amount	$ 1,262,757	$ 1,204,960
Intangible assets, exclusive of goodwill, gross	1,523,486	1,465,689
Indefinite-lived intangible assets, gross carrying amount	260,729	260,729
Finite-lived intangible assets, accumulated amortization	(415,915)	(339,746)
Intangible assets, accumulated impairment loss	(38,507)	(38,507)
Finite-lived intangible assets, net carrying amount	846,842	865,214
Intangible assets, net, exclusive of goodwill	1,069,064	1,087,436
Indefinite-lived intangible assets	222,222	222,222
Solid Waste Collection and Transportation Permits [Member]
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Indefinite-lived intangible assets, gross carrying amount	158,591	158,591
Intangible assets, accumulated impairment loss
Indefinite-lived intangible assets	158,591	158,591
Material Recycling Facility Permits [Member]
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Indefinite-lived intangible assets, gross carrying amount	42,283	42,283
Intangible assets, accumulated impairment loss
Indefinite-lived intangible assets	42,283	42,283
Exploration and Production Facility Permits [Member]
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Indefinite-lived intangible assets, gross carrying amount	59,855	59,855
Intangible assets, accumulated impairment loss	(38,507)	(38,507)
Indefinite-lived intangible assets	21,348	21,348
Long-term Franchise Agreements and Contracts [Member]
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross carrying amount	483,749	481,293
Finite-lived intangible assets, accumulated amortization	(150,691)	(123,591)
Finite-lived intangible assets, net carrying amount	333,058	357,702
Customer Lists [Member]
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross carrying amount	429,801	405,683
Finite-lived intangible assets, accumulated amortization	(219,104)	(180,440)
Finite-lived intangible assets, net carrying amount	210,697	225,243
Permits and Other [Member]
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross carrying amount	349,207	317,984
Finite-lived intangible assets, accumulated amortization	(46,120)	(35,715)
Finite-lived intangible assets, net carrying amount	$ 303,087	$ 282,269

Intangible Assets, Net (Estimat

Intangible Assets, Net (Estimated Future Amortization Expense of Amortizable Intangible Assets) (Detail) $ in Thousands	Sep. 30, 2018USD ($)
Intangible Assets, Net [Abstract]
For the year ending December 31, 2018	$ 105,991
For the year ending December 31, 2019	95,653
For the year ending December 31, 2020	85,751
For the year ending December 31, 2021	75,561
For the year ending December 31, 2022	$ 65,904

Long-Term Debt (Narrative) (Det

Long-Term Debt (Narrative) (Detail) - USD ($)		Apr. 02, 2018	Sep. 30, 2018	Aug. 01, 2018	Jul. 31, 2018	Feb. 28, 2018	Dec. 31, 2017	Apr. 20, 2017
Debt Instrument [Line Items]
Long term debt			$ 3,763,330,000				$ 3,926,321,000
Cash and cash equivalents			244,389,000				433,815,000
Credit Agreement [Member]
Debt Instrument [Line Items]
Credit facility			$ 3,200,000,000
Covenant decription			During the continuance of an event of default, the Lenders may take a number of actions, including, among others, declaring the entire amount then outstanding under the Credit Agreement to be due and payable. The Credit Agreement includes a financial covenant limiting, as of the last day of each fiscal quarter, the ratio of (a) (i) Consolidated Total Funded Debt (as defined in the Credit Agreement) as of such date less (ii) the sum of cash and cash equivalents of the Company and its subsidiaries on a dollar-for-dollar basis as of such date in excess of $50,000 up to a maximum of $200,000 (such that the maximum amount of reduction pursuant to this calculation does not exceed $150,000) to (b) Consolidated EBITDA (as defined in the Credit Agreement), measured for the preceding 12 months (the "Leverage Ratio"), to not more than 3.50 to 1.00 (or 3.75 to 1.00 during material acquisition periods, subject to certain limitations). The Credit Agreement also includes a financial covenant requiring the ratio of Consolidated EBIT (as defined in the Credit Agreement) to Consolidated Total Interest Expense (as defined in the Credit Agreement), in each case, measured for the preceding 12 months, to be not less than 2.75 to 1.00.
Maturity date			Mar. 21, 2023
Credit Agreement [Member] | Letter of Credit [Member]
Debt Instrument [Line Items]
Credit facility			$ 500,000,000
Credit Agreement [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Credit facility			1,562,500,000
Long term debt	[1]		$ 169,950,000				192,101,000
Interest rate	[1]		2.93%
Credit Agreement [Member] | Term Loan Facility [Member]
Debt Instrument [Line Items]
Credit facility			$ 1,637,500,000
Credit Agreement [Member] | Minimum [Member]
Debt Instrument [Line Items]
Required interest coverage ratio			2.75
Credit Agreement [Member] | Maximum [Member]
Debt Instrument [Line Items]
Reguired leverage ratio during material acquisition period			3.75
Required leverage ratio			3.50
Credit Agreement [Member] | Maximum [Member] | Swing Line Loans [Member]
Debt Instrument [Line Items]
Swing line loans			$ 75,000,000
2016 Master Note Purchase Agreement [Member]
Debt Instrument [Line Items]
Maximum limit of aggregate principal amount of notes outstanding			1,500,000,000
Tax-exempt Bonds [Member]
Debt Instrument [Line Items]
Long term debt	[1]		$ 15,930,000				95,430,000
Interest rate	[1]		1.61%
Notes Payable to Sellers and Other Third Parties [Member]
Debt Instrument [Line Items]
Long term debt	[1]		$ 14,950,000				26,290,000
Notes Payable to Sellers and Other Third Parties [Member] | Minimum [Member]
Debt Instrument [Line Items]
Interest rate	[1]		2.75%
Notes Payable to Sellers and Other Third Parties [Member] | Maximum [Member]
Debt Instrument [Line Items]
Interest rate	[1]		24.81%
Pennsylvania Economic Development Corporation IRB Bond [Member]
Debt Instrument [Line Items]
Principal balance						$ 35,000,000
Mission Economic Development Corporation IRB Bond [Member]
Debt Instrument [Line Items]
Principal balance						$ 24,000,000
Seneca County Industrial Development Agency IRB Bond [Member]
Debt Instrument [Line Items]
Principal balance					$ 5,000,000
West Valley Tax-Exempt Bond [Member]
Debt Instrument [Line Items]
Principal balance				$ 15,500,000
Senior Notes [Member] | 2016 Master Note Purchase Agreement [Member]
Debt Instrument [Line Items]
Aggregate principal amount			$ 1,150,000,000
Senior Notes [Member] | Assumed 2008 Note Purchase Agreement [Member]
Debt Instrument [Line Items]
Maximum limit of aggregate principal amount of notes outstanding			1,250,000,000
Aggregate principal amount			$ 775,000,000
Senior Notes [Member] | Senior Notes due 2018 [Member]
Debt Instrument [Line Items]
Long term debt							50,000,000
Maturity date			Apr. 2, 2018
Interest rate		4.00%
Maturities of senior notes		$ 50,000,000
Senior Notes [Member] | Senior Notes due 2019 [Member]
Debt Instrument [Line Items]
Long term debt			$ 175,000,000				175,000,000
Interest rate			5.25%
Aggregate principal amount			$ 175,000,000
Debt instrument maturity date year			2,019
Senior Notes [Member] | Senior Notes due 2021 [Member]
Debt Instrument [Line Items]
Long term debt			$ 100,000,000				100,000,000
Interest rate			4.64%
Aggregate principal amount			$ 100,000,000
Debt instrument maturity date year			2,021
Senior Notes [Member] | New Senior Notes due 2021 [Member]
Debt Instrument [Line Items]
Long term debt			$ 150,000,000				150,000,000
Maturity date			Jun. 1, 2021
Interest rate			2.39%
Aggregate principal amount			$ 150,000,000
Senior Notes [Member] | Senior Notes due 2022 [Member]
Debt Instrument [Line Items]
Long term debt			$ 125,000,000				125,000,000
Interest rate			3.09%
Aggregate principal amount			$ 125,000,000
Debt instrument maturity date year			2,022
Senior Notes [Member] | Senior Notes due 2023 [Member]
Debt Instrument [Line Items]
Long term debt			$ 200,000,000				200,000,000
Maturity date			Jun. 1, 2023
Interest rate			2.75%
Aggregate principal amount			$ 200,000,000
Senior Notes [Member] | Senior Notes due 2024 [Member]
Debt Instrument [Line Items]
Long term debt			$ 150,000,000				150,000,000
Maturity date			Apr. 20, 2024
Interest rate			3.24%
Aggregate principal amount								$ 150,000,000
Senior Notes [Member] | Senior Notes due 2025 [Member]
Debt Instrument [Line Items]
Long term debt			$ 375,000,000				375,000,000
Interest rate			3.41%
Aggregate principal amount			$ 375,000,000
Debt instrument maturity date year			2,025
Senior Notes [Member] | Senior Notes due 2026 [Member]
Debt Instrument [Line Items]
Long term debt			$ 400,000,000				400,000,000
Maturity date			Jun. 1, 2026
Interest rate			3.03%
Aggregate principal amount			$ 400,000,000
Senior Notes [Member] | Senior Notes due 2027 [Member]
Debt Instrument [Line Items]
Long term debt			$ 250,000,000				250,000,000
Maturity date			Apr. 20, 2027
Interest rate			3.49%
Aggregate principal amount								250,000,000
Senior Notes [Member] | 2017 A Senior Notes [Member]
Debt Instrument [Line Items]
Aggregate principal amount			$ 400,000,000					$ 400,000,000
Term Loan Facility [Member] | Credit Agreement [Member]
Debt Instrument [Line Items]
Long term debt	[1]		$ 1,637,500,000				1,637,500,000
Interest rate	[1]		3.34%
Term Loan Facility [Member] | Credit Agreement [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Credit facility maximum increase to borrowing capacity			$ 500,000,000
Maximum amount of increase in commitments under the credit agreement			3,700,000,000
Credit Agreement Covenant [Member] | Credit Agreement [Member] | Minimum [Member]
Debt Instrument [Line Items]
Cash and cash equivalents			50,000,000
Credit Agreement Covenant [Member] | Credit Agreement [Member] | Maximum [Member]
Debt Instrument [Line Items]
Cash and cash equivalents			200,000,000
Credit Agreement Covenant [Member] | Other Assets [Member] | Credit Agreement [Member] | Maximum [Member]
Debt Instrument [Line Items]
Cash and cash equivalents			$ 150,000,000
Base Rate [Member] | Canadian Prime Rate Loans and Swing Line Loans [Member] | Minimum [Member]
Debt Instrument [Line Items]
Margin rate for loans			0.00%
Base Rate [Member] | Canadian Prime Rate Loans and Swing Line Loans [Member] | Maximum [Member]
Debt Instrument [Line Items]
Margin rate for loans			0.50%
LIBOR [Member] | Credit Agreement [Member] | Term Loan Facility [Member]
Debt Instrument [Line Items]
Long term debt			$ 1,637,500,000				$ 1,637,500,000
Interest rate			3.34%				2.77%
LIBOR [Member] | Drawing Fees for Bankers' Acceptance and BA Loans and Letter of Credit [Member] | Minimum [Member]
Debt Instrument [Line Items]
Margin rate for loans			1.00%
LIBOR [Member] | Drawing Fees for Bankers' Acceptance and BA Loans and Letter of Credit [Member] | Maximum [Member]
Debt Instrument [Line Items]
Margin rate for loans			1.50%
Canadian Prime Rate [Member] | Credit Agreement [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Credit facility outstanding							$ 16,739,000
Interest rate applicable							3.45%
Canadian Bankers Acceptance Loan [Member] | Credit Agreement [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Credit facility outstanding			$ 169,950,000				$ 175,362,000
Interest rate applicable			2.93%				2.64%
[1]	Interest rates represent the interest rates incurred at September 30, 2018

Long-Term Debt (Long-Term Debt)

Long-Term Debt (Long-Term Debt) (Detail) - USD ($) $ in Thousands		Sep. 30, 2018	Apr. 02, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Total debt		$ 3,763,330		$ 3,926,321
Less - current portion		(1,753)		(11,659)
Less - debt issuance costs		(14,368)		(15,090)
Long-term debt and notes payable		3,747,209		3,899,572
Credit Agreement [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Total debt	[1]	$ 169,950		192,101
Interest rate	[1]	2.93%
Credit Agreement [Member] | Term Loan Facility [Member]
Debt Instrument [Line Items]
Total debt	[1]	$ 1,637,500		1,637,500
Interest rate	[1]	3.34%
Senior Notes due 2018 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Total debt				50,000
Interest rate			4.00%
Senior Notes due 2019 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Total debt		$ 175,000		175,000
Interest rate		5.25%
Senior Notes due 2021 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Total debt		$ 100,000		100,000
Interest rate		4.64%
New Senior Notes due 2021 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Total debt		$ 150,000		150,000
Interest rate		2.39%
Senior Notes due 2022 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Total debt		$ 125,000		125,000
Interest rate		3.09%
Senior Notes due 2023 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Total debt		$ 200,000		200,000
Interest rate		2.75%
Senior Notes due 2024 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Total debt		$ 150,000		150,000
Interest rate		3.24%
Senior Notes due 2025 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Total debt		$ 375,000		375,000
Interest rate		3.41%
Senior Notes due 2026 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Total debt		$ 400,000		400,000
Interest rate		3.03%
Senior Notes due 2027 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Total debt		$ 250,000		250,000
Interest rate		3.49%
Tax-exempt Bonds [Member]
Debt Instrument [Line Items]
Total debt	[1]	$ 15,930		95,430
Interest rate	[1]	1.61%
Notes Payable to Sellers and Other Third Parties [Member]
Debt Instrument [Line Items]
Total debt	[1]	$ 14,950		$ 26,290
Notes Payable to Sellers and Other Third Parties [Member] | Minimum [Member]
Debt Instrument [Line Items]
Interest rate	[1]	2.75%
Notes Payable to Sellers and Other Third Parties [Member] | Maximum [Member]
Debt Instrument [Line Items]
Interest rate	[1]	24.81%
[1]	Interest rates represent the interest rates incurred at September 30, 2018

Long-Term Debt (Details of the

Long-Term Debt (Details of the Company's Credit Agreement) (Details) - USD ($) $ in Thousands		9 Months Ended	12 Months Ended
		Sep. 30, 2018	Dec. 31, 2017
Line of Credit Facility [Line Items]
Amount drawn		$ 3,763,330	$ 3,926,321
Revolving Credit Facility [Member] | Credit Agreement [Member]
Line of Credit Facility [Line Items]
Available		$ 1,252,021	$ 1,149,813
Commitment - rate applicable		0.12%	0.15%
Amount drawn	[1]	$ 169,950	$ 192,101
Interest rate applicable	[1]	2.93%
Letter of Credit [Member] | Credit Agreement [Member]
Line of Credit Facility [Line Items]
Letter of credit		$ 140,529	220,586
LIBOR [Member] | Term Loan Facility [Member] | Credit Agreement [Member]
Line of Credit Facility [Line Items]
Amount drawn		$ 1,637,500	$ 1,637,500
Interest rate applicable		3.34%	2.77%
Canadian Prime Rate [Member] | Revolving Credit Facility [Member] | Credit Agreement [Member]
Line of Credit Facility [Line Items]
Amount drawn			$ 16,739
Interest rate applicable			3.45%
Canadian Bankers Acceptance Loan [Member] | Revolving Credit Facility [Member] | Credit Agreement [Member]
Line of Credit Facility [Line Items]
Amount drawn		$ 169,950	$ 175,362
Interest rate applicable		2.93%	2.64%
[1]	Interest rates represent the interest rates incurred at September 30, 2018

Segment Reporting (Narrative) (

Segment Reporting (Narrative) (Detail)	9 Months Ended
	Sep. 30, 2018customersegment
Segment Reporting [Abstract]
Number of contracts or customers accounted for more than 10% of the Company's total revenues at the consolidated or reportable segment level | customer	0
Number of operating segments	6
Number of reportable segments	6

Segment Reporting (Summary of F

Segment Reporting (Summary of Financial Information Concerning Company's Reportable Segments) (Detail) $ in Thousands		3 Months Ended				9 Months Ended
		Sep. 30, 2018USD ($)		Sep. 30, 2017USD ($)		Sep. 30, 2018USD ($)segment	Sep. 30, 2017USD ($)
Segment Reporting Information [Line Items]
Revenue		$ 1,281,110		$ 1,206,478		$ 3,661,209	$ 3,473,313
Segment EBITDA		405,974	[1]	383,156	[1]	$ 1,141,680	1,065,311
Number of operating segments | segment						6
Reportable Segments [Member]
Segment Reporting Information [Line Items]
Revenue		1,471,286		1,371,990		$ 4,185,656	3,957,311
Segment EBITDA		414,260		388,907		1,156,048	1,097,846
Intercompany Revenue [Member]
Segment Reporting Information [Line Items]
Revenue		(190,176)	[2]	(165,512)	[2]	(524,447)	(483,998)
Southern [Member]
Segment Reporting Information [Line Items]
Revenue		283,040		280,528		839,489	846,034
Segment EBITDA		70,159	[1]	63,171	[1]	207,853	199,280
Southern [Member] | Reportable Segments [Member]
Segment Reporting Information [Line Items]
Revenue		321,306		317,059		951,313	957,506
Southern [Member] | Intercompany Revenue [Member]
Segment Reporting Information [Line Items]
Revenue		(38,266)	[2]	(36,531)	[2]	(111,824)	(111,472)
Western [Member]
Segment Reporting Information [Line Items]
Revenue		271,018		261,877		779,880	754,959
Segment EBITDA		86,174	[1]	84,861	[1]	240,006	247,475
Western [Member] | Reportable Segments [Member]
Segment Reporting Information [Line Items]
Revenue		303,614		292,222		874,464	845,176
Western [Member] | Intercompany Revenue [Member]
Segment Reporting Information [Line Items]
Revenue		(32,596)	[2]	(30,345)	[2]	(94,584)	(90,217)
Eastern [Member]
Segment Reporting Information [Line Items]
Revenue		289,497		246,267		802,318	718,302
Segment EBITDA		83,721	[1]	74,018	[1]	225,950	209,315
Eastern [Member] | Reportable Segments [Member]
Segment Reporting Information [Line Items]
Revenue		353,844		292,124		966,571	851,880
Eastern [Member] | Intercompany Revenue [Member]
Segment Reporting Information [Line Items]
Revenue		(64,347)	[2]	(45,857)	[2]	(164,253)	(133,578)
Canada [Member]
Segment Reporting Information [Line Items]
Revenue		187,054		197,055		543,867	546,149
Segment EBITDA		68,819	[1]	74,369	[1]	195,390	200,283
Canada [Member] | Reportable Segments [Member]
Segment Reporting Information [Line Items]
Revenue		211,682		224,166		615,157	621,995
Canada [Member] | Intercompany Revenue [Member]
Segment Reporting Information [Line Items]
Revenue		(24,628)	[2]	(27,111)	[2]	(71,290)	(75,846)
Central [Member]
Segment Reporting Information [Line Items]
Revenue		185,271	[3]	166,360	[3]	514,080	470,087
Segment EBITDA		70,288	[1],[3]	64,607	[1],[3]	191,840	177,975
Central [Member] | Reportable Segments [Member]
Segment Reporting Information [Line Items]
Revenue		213,492	[3]	190,210	[3]	591,417	536,803
Central [Member] | Intercompany Revenue [Member]
Segment Reporting Information [Line Items]
Revenue		(28,221)	[2],[3]	(23,850)	[2],[3]	(77,337)	(66,716)
Exploration and Production [Member]
Segment Reporting Information [Line Items]
Revenue		65,230		54,391		181,575	137,782
Segment EBITDA		35,099	[1]	27,881	[1]	95,009	63,518
Exploration and Production [Member] | Reportable Segments [Member]
Segment Reporting Information [Line Items]
Revenue		67,348		56,209		186,734	143,951
Exploration and Production [Member] | Intercompany Revenue [Member]
Segment Reporting Information [Line Items]
Revenue		(2,118)	[2]	(1,818)	[2]	(5,159)	(6,169)
Corporate [Member]
Segment Reporting Information [Line Items]
Revenue	[3]
Segment EBITDA		$ (8,286)	[1],[3]	(5,751)	[1],[3]	$ (14,368)	$ (32,535)
Corporate [Member] | Reportable Segments [Member]
Segment Reporting Information [Line Items]
Revenue	[3]
Corporate [Member] | Intercompany Revenue [Member]
Segment Reporting Information [Line Items]
Revenue	[2],[3]
[1]	For those items included in the determination of segment EBITDA, the accounting policies of the segments are the same as those described in the Company's most recent Annual Report on Form 10-K.
[2]	Intercompany revenues reflect each segment's total intercompany sales, including intercompany sales within a segment and between segments. Transactions within and between segments are generally made on a basis intended to reflect the market value of the service.
[3]	Corporate functions include accounting, legal, tax, treasury, information technology, risk management, human resources, training and other administrative functions. Amounts reflected are net of allocations to the six operating segments.

Segment Reporting (Total Assets

Segment Reporting (Total Assets for Reportable Segments) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Assets	$ 12,192,066	$ 12,014,681
Southern [Member]
Segment Reporting Information [Line Items]
Assets	2,778,123	2,718,296
Western [Member]
Segment Reporting Information [Line Items]
Assets	1,583,561	1,573,955
Eastern [Member]
Segment Reporting Information [Line Items]
Assets	2,348,438	2,024,527
Canada [Member]
Segment Reporting Information [Line Items]
Assets	2,562,659	2,677,557
Central [Member]
Segment Reporting Information [Line Items]
Assets	1,452,607	1,297,118
Exploration and Production [Member]
Segment Reporting Information [Line Items]
Assets	974,049	981,980
Corporate [Member]
Segment Reporting Information [Line Items]
Assets	$ 492,629	$ 741,248

Segment Reporting (Changes in G

Segment Reporting (Changes in Goodwill by Reportable Segment) (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Goodwill [Line Items]
Goodwill, Beginning Balance	$ 4,681,774	$ 4,390,261
Goodwill acquired	169,950	309,031
Goodwill divested		(36,486)
Impairment loss		(77,343)
Goodwill adjustment for assets sold		2,526
Goodwill adjustment for assets held for sale	10,194	(11,080)
Impact of changes in foreign currency	(48,622)	111,439
Goodwill, Ending Balance	4,813,296	4,688,348
Southern [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance	1,436,320	1,470,023
Goodwill acquired	4,800	7,484
Goodwill divested		(31,543)
Goodwill adjustment for assets sold		2,205
Goodwill adjustment for assets held for sale	10,194	(11,080)
Goodwill, Ending Balance	1,451,314	1,437,089
Western [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance	397,508	376,537
Goodwill acquired	666	20,906
Goodwill, Ending Balance	398,174	397,443
Eastern [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance	804,133	533,160
Goodwill acquired	122,136	272,501
Goodwill divested		(4,276)
Goodwill adjustment for assets sold		321
Goodwill, Ending Balance	926,269	801,706
Canada [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance	1,575,538	1,465,274
Goodwill acquired	151	7,127
Impact of changes in foreign currency	(48,622)	111,439
Goodwill, Ending Balance	1,527,067	1,583,840
Central [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance	468,275	467,924
Goodwill acquired	42,197	1,013
Goodwill divested		(667)
Goodwill, Ending Balance	$ 510,472	468,270
Exploration and Production [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance		77,343
Goodwill acquired
Goodwill divested
Impairment loss		(77,343)
Goodwill adjustment for assets sold
Goodwill adjustment for assets held for sale
Impact of changes in foreign currency
Goodwill, Ending Balance

Segment Reporting (Reconciliati

Segment Reporting (Reconciliation of Primary Measure of Segment Profitability to Income Before Income Tax Provision) (Detail) - USD ($) $ in Thousands	3 Months Ended				9 Months Ended
	Sep. 30, 2018		Sep. 30, 2017		Sep. 30, 2018	Sep. 30, 2017
Segment EBITDA	$ 405,974	[1]	$ 383,156	[1]	$ 1,141,680	$ 1,065,311
Depreciation	(148,232)		(136,941)		(423,866)	(395,008)
Amortization of intangibles	(26,871)		(26,613)		(79,444)	(76,886)
Impairments and other operating items	1,998		(832)		(6,106)	(141,333)
Interest expense	(32,078)		(32,471)		(96,874)	(92,763)
Interest income	1,467		1,656		3,677	3,131
Other income, net	732		1,709		2,376	3,561
Foreign currency transaction gain (loss)	(132)		(1,864)		(323)	(3,502)
Income before income tax provision	202,858		187,800		541,120	362,511
Southern [Member]
Segment EBITDA	70,159	[1]	63,171	[1]	207,853	199,280
Western [Member]
Segment EBITDA	86,174	[1]	84,861	[1]	240,006	247,475
Eastern [Member]
Segment EBITDA	83,721	[1]	74,018	[1]	225,950	209,315
Canada [Member]
Segment EBITDA	68,819	[1]	74,369	[1]	195,390	200,283
Central [Member]
Segment EBITDA	70,288	[1],[2]	64,607	[1],[2]	191,840	177,975
Exploration and Production [Member]
Segment EBITDA	35,099	[1]	27,881	[1]	95,009	63,518
Corporate [Member]
Segment EBITDA	(8,286)	[1],[2]	(5,751)	[1],[2]	(14,368)	(32,535)
Reportable Segments [Member]
Segment EBITDA	$ 414,260		$ 388,907		$ 1,156,048	$ 1,097,846
[1]	For those items included in the determination of segment EBITDA, the accounting policies of the segments are the same as those described in the Company's most recent Annual Report on Form 10-K.
[2]	Corporate functions include accounting, legal, tax, treasury, information technology, risk management, human resources, training and other administrative functions. Amounts reflected are net of allocations to the six operating segments.

Derivative Financial Instrume_3

Derivative Financial Instruments (Narrative) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)agreement	Sep. 30, 2017USD ($)
Derivative Financial Instruments [Abstract]
Number of interest rate swap agreements	16
Number of fuel hedge agreements	1
Ineffectiveness recognized on the fuel hedges | $	$ 0	$ 0

Derivative Financial Instrume_4

Derivative Financial Instruments (Company's Derivative Instruments of Interest Rate Swaps) (Details) - LIBOR [Member] $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)
Interest Rate Swap One [Member]
Derivative [Line Items]
Date entered	2014-04
Notional amount	$ 100,000
Fixed interest rate paid	1.80%	[1]
Variable interest rate received	1-month LIBOR
Effective date	2014-07
Expiration date	2019-07
Interest Rate Swap Two [Member]
Derivative [Line Items]
Date entered	2014-05
Notional amount	$ 50,000
Fixed interest rate paid	2.344%	[1]
Variable interest rate received	1-month LIBOR
Effective date	2015-10
Expiration date	2020-10
Interest Rate Swap Three [Member]
Derivative [Line Items]
Date entered	2014-05
Notional amount	$ 25,000
Fixed interest rate paid	2.326%	[1]
Variable interest rate received	1-month LIBOR
Effective date	2015-10
Expiration date	2020-10
Interest Rate Swap Four [Member]
Derivative [Line Items]
Date entered	2014-05
Notional amount	$ 50,000
Fixed interest rate paid	2.35%	[1]
Variable interest rate received	1-month LIBOR
Effective date	2015-10
Expiration date	2020-10
Interest Rate Swap Five [Member]
Derivative [Line Items]
Date entered	2014-05
Notional amount	$ 50,000
Fixed interest rate paid	2.35%	[1]
Variable interest rate received	1-month LIBOR
Effective date	2015-10
Expiration date	2020-10
Interest Rate Swap Six [Member]
Derivative [Line Items]
Date entered	2016-04
Notional amount	$ 100,000
Fixed interest rate paid	1.00%	[1]
Variable interest rate received	1-month LIBOR
Effective date	2017-02
Expiration date	2020-02
Interest Rate Swap Seven [Member]
Derivative [Line Items]
Date entered	2016-06
Notional amount	$ 75,000
Fixed interest rate paid	0.85%	[1]
Variable interest rate received	1-month LIBOR
Effective date	2017-02
Expiration date	2020-02
Interest Rate Swap Eight [Member]
Derivative [Line Items]
Date entered	2016-06
Notional amount	$ 150,000
Fixed interest rate paid	0.95%	[1]
Variable interest rate received	1-month LIBOR
Effective date	2018-01
Expiration date	2021-01
Interest Rate Swap Nine [Member]
Derivative [Line Items]
Date entered	2016-06
Notional amount	$ 150,000
Fixed interest rate paid	0.95%	[1]
Variable interest rate received	1-month LIBOR
Effective date	2018-01
Expiration date	2021-01
Interest Rate Swap Ten [Member]
Derivative [Line Items]
Date entered	2016-07
Notional amount	$ 50,000
Fixed interest rate paid	0.90%	[1]
Variable interest rate received	1-month LIBOR
Effective date	2018-01
Expiration date	2021-01
Interest Rate Swap Eleven [Member]
Derivative [Line Items]
Date entered	2016-07
Notional amount	$ 50,000
Fixed interest rate paid	0.89%	[1]
Variable interest rate received	1-month LIBOR
Effective date	2018-01
Expiration date	2021-01
Interest Rate Swap Twelve [Member]
Derivative [Line Items]
Date entered	2017-08
Notional amount	$ 100,000
Fixed interest rate paid	1.90%	[1]
Variable interest rate received	1-month LIBOR
Effective date	2019-07
Expiration date	2022-07
Interest Rate Swap Thirteen [Member]
Derivative [Line Items]
Date entered	2017-08
Notional amount	$ 200,000
Fixed interest rate paid	2.20%	[1]
Variable interest rate received	1-month LIBOR
Effective date	2020-10
Expiration date	2025-10
Interest Rate Swap Fourteen [Member]
Derivative [Line Items]
Date entered	2017-08
Notional amount	$ 150,000
Fixed interest rate paid	1.95%	[1]
Variable interest rate received	1-month LIBOR
Effective date	2020-02
Expiration date	2023-02
Interest Rate Swap Fifteen [Member]
Derivative [Line Items]
Date entered	2018-06
Notional amount	$ 200,000
Fixed interest rate paid	2.925%	[1]
Variable interest rate received	1-month LIBOR
Effective date	2020-10
Expiration date	2025-10
Interest Rate Swap Sixteen [Member]
Derivative [Line Items]
Date entered	2018-06
Notional amount	$ 200,000
Fixed interest rate paid	2.925%	[1]
Variable interest rate received	1-month LIBOR
Effective date	2020-10
Expiration date	2025-10
[1]	Plus applicable margin.

Derivative Financial Instrume_5

Derivative Financial Instruments (Company's Derivative Instruments of Fuel Hedge Agreements) (Details) - Fuel [Member] - Fuel Hedge Agreement One [Member]	9 Months Ended
	Sep. 30, 2018gal / M$ / gal
Derivative [Line Items]
Date entered	2016-07
Notional amount (in gallons per month) | gal / M	1,000,000
Diesel rate paid fixed (per gallon) | $ / gal	2.6345
Diesel rate received variable	DOE Diesel Fuel Index*	[1]
Effective date	2018-01
Expiration date	2018-12
[1]	If the national U.S. on-highway average price for a gallon of diesel fuel ("average price"), as published by the U.S. Department of Energy ("DOE"), exceeds the contract price per gallon, the Company receives the difference between the average price and the contract price (multiplied by the notional number of gallons) from the counterparty. If the average price is less than the contract price per gallon, the Company pays the difference to the counterparty.

Derivative Financial Instrume_6

Derivative Financial Instruments (Fair Values of Derivative Instruments Designated as Cash Flow Hedges) (Details) - USD ($) $ in Thousands	Sep. 30, 2018		Dec. 31, 2017
Derivatives, Fair Value [Line Items]
Derivatives designated as cash flow hedges, asset derivatives	$ 39,403		$ 24,255
Derivatives designated as cash flow hedges, liability derivatives			(1,396)
Interest Rate Swap [Member] | Accrued Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivatives designated as cash flow hedges, liability derivatives			(903)
Interest Rate Swap [Member] | Other Long-term Liabilities [Member}
Derivatives, Fair Value [Line Items]
Derivatives designated as cash flow hedges, liability derivatives			(493)
Interest Rate Swap [Member] | Prepaid Expenses and Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives designated as cash flow hedges, asset derivatives	11,380	[1]	5,193
Interest Rate Swap [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives designated as cash flow hedges, asset derivatives	25,834		15,182
Fuel [Member] | Commodity Contract [Member] | Prepaid Expenses and Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives designated as cash flow hedges, asset derivatives	$ 2,189	[2]	$ 3,880
[1]	Represents the estimated amount of the existing unrealized gains on interest rate swaps as of September 30, 2018 (based on the interest rate yield curve at that date), included in AOCIL expected to be reclassified into pre-tax earnings within the next 12 months. The actual amounts reclassified into earnings are dependent on future movements in interest rates.
[2]	Represents the estimated amount of the existing unrealized gains on the fuel hedge as of September 30, 2018 (based on the forward DOE diesel fuel index curve at that date), included in AOCIL expected to be reclassified into pre-tax earnings within the next 12 months. The actual amounts reclassified into earnings are dependent on future movements in diesel fuel prices.

Derivative Financial Instrume_7

Derivative Financial Instruments (Impact of Cash Flow Hedges on Results of Operations, Comprehensive Income (Loss) and Accumulated Other Comprehensive Income (Loss)) (Details) - Cash Flow Hedging [Member] - USD ($) $ in Thousands	3 Months Ended				9 Months Ended
	Sep. 30, 2018		Sep. 30, 2017		Sep. 30, 2018	Sep. 30, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain or (loss) recognized as AOCIL on derivatives, net of tax (effective portion)	$ 856	[1]	$ 1,319	[1]	$ 13,860	$ (806)
Amount of (gain) or loss reclassified from AOCIL into earnings, net of tax (effective portion)	1,786	[2],[3]	863	[2],[3]	(1,721)	3,433
Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (gain) or loss reclassified from AOCIL into earnings, net of tax (effective portion)	3,145	[2],[3]	376	[2],[3]	1,769	1,729
Cost Of Operations [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (gain) or loss reclassified from AOCIL into earnings, net of tax (effective portion)	(1,359)	[2],[3]	487	[2],[3]	(3,490)	1,704
Interest Rate Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain or (loss) recognized as AOCIL on derivatives, net of tax (effective portion)	634	[1]	(361)	[1]	11,634	224
Fuel [Member] | Commodity Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain or (loss) recognized as AOCIL on derivatives, net of tax (effective portion)	$ 222	[1]	$ 1,680	[1]	$ 2,226	$ (1,030)
[1]	In accordance with the derivatives and hedging guidance, the effective portions of the changes in fair values of interest rate swaps and fuel hedges have been recorded in equity as a component of AOCIL. As the critical terms of the interest rate swaps match the underlying debt being hedged, no ineffectiveness is recognized on these swaps and, therefore, all unrealized changes in fair value are recorded in AOCIL. Because changes in the actual price of diesel fuel and changes in the DOE index price do not offset exactly each reporting period, the Company assesses whether the fuel hedges are highly effective using the cumulative dollar offset approach.
[2]	Amounts reclassified from AOCIL into earnings related to realized gains and losses on interest rate swaps are recognized when interest payments or receipts occur related to the swap contracts, which correspond to when interest payments are made on the Company's hedged debt.
[3]	Amounts reclassified from AOCIL into earnings related to realized gains and losses on the fuel hedges are recognized when settlement payments or receipts occur related to the hedge contracts, which correspond to when the underlying fuel is consumed.

Fair Value of Financial Instr_3

Fair Value of Financial Instruments (Carrying Values and Fair Values of Debt Instruments) (Detail) - USD ($) $ in Thousands		9 Months Ended
		Sep. 30, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Carrying value of senior notes		$ 3,763,330	$ 3,926,321
Senior Notes [Member] | Senior Notes due 2018 [Member]
Debt Instrument [Line Items]
Carrying value of senior notes			50,000
Fair value of senior notes	[1]		50,223
Senior note year due		2,018
Senior Notes [Member] | Senior Notes due 2019 [Member]
Debt Instrument [Line Items]
Carrying value of senior notes		$ 175,000	175,000
Fair value of senior notes	[1]	$ 178,150	182,547
Senior note year due		2,019
Senior Notes [Member] | Senior Notes due 2021 [Member]
Debt Instrument [Line Items]
Carrying value of senior notes		$ 100,000	100,000
Fair value of senior notes	[1]	$ 101,780	104,985
Senior note year due		2,021
Senior Notes [Member] | New Senior Notes due 2021 [Member]
Debt Instrument [Line Items]
Carrying value of senior notes		$ 150,000	150,000
Fair value of senior notes	[1]	$ 144,299	146,855
Senior note year due		2,021
Senior Notes [Member] | Senior Notes due 2022 [Member]
Debt Instrument [Line Items]
Carrying value of senior notes		$ 125,000	125,000
Fair value of senior notes	[1]	$ 121,062	124,532
Senior note year due		2,022
Senior Notes [Member] | Senior Notes due 2023 [Member]
Debt Instrument [Line Items]
Carrying value of senior notes		$ 200,000	200,000
Fair value of senior notes	[1]	$ 188,988	194,660
Senior note year due		2,023
Senior Notes [Member] | Senior Notes due 2024 [Member]
Debt Instrument [Line Items]
Carrying value of senior notes		$ 150,000	150,000
Fair value of senior notes	[1]	$ 143,651	149,133
Senior note year due		2,024
Senior Notes [Member] | Senior Notes due 2025 [Member]
Debt Instrument [Line Items]
Carrying value of senior notes		$ 375,000	375,000
Fair value of senior notes	[1]	$ 358,141	375,311
Senior note year due		2,025
Senior Notes [Member] | Senior Notes due 2026 [Member]
Debt Instrument [Line Items]
Carrying value of senior notes		$ 400,000	400,000
Fair value of senior notes	[1]	$ 369,921	388,760
Senior note year due		2,026
Senior Notes [Member] | Senior Notes due 2027 [Member]
Debt Instrument [Line Items]
Carrying value of senior notes		$ 250,000	250,000
Fair value of senior notes	[1]	$ 236,409	$ 250,029
Senior note year due		2,027
[1]	Senior Notes are classified as Level 2 within the fair value hierarchy. Fair value is based on quotes of bonds with similar ratings in similar industries.

Net Income Per Share Informat_3

Net Income Per Share Information (Basic and Diluted Net Income Per Common Share) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Numerator:
Net income attributable to Waste Connections for basic and diluted earnings per share	$ 150,843	$ 123,227	$ 414,393	$ 261,732
Denominator:
Basic shares outstanding	263,628,838	263,443,064	263,657,274	263,298,839
Dilutive effect of equity-based awards	765,919	856,408	719,046	810,544
Diluted shares outstanding	264,394,757	264,299,472	264,376,320	264,109,383

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Detail) - $ / gal	Sep. 30, 2018	Dec. 31, 2017
Fair Value [Abstract]
Minimum range of DOE index curve used in DCF model	3.36	2.95
Maximum range of DOE index curve used in DCF model	3.39	3
Weighted average DOE index curve used in DCF model	3.38	2.96

Fair Value Measurements (Assets

Fair Value Measurements (Assets and Liabilities Measured at Fair Value on Recurring Basis) (Detail) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Restricted cash and investments	$ 126,221	$ 165,592
Contingent consideration	(55,024)	(47,285)
Interest Rate Swap [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instrument - net	37,214	18,979
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Restricted cash and investments	126,221	165,592
Fair Value, Inputs, Level 2 [Member] | Interest Rate Swap [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instrument - net	37,214	18,979
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration	(55,024)	(47,285)
Fuel [Member] | Commodity Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instrument - net	2,189	3,880
Fuel [Member] | Fair Value, Inputs, Level 3 [Member] | Commodity Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instrument - net	$ 2,189	$ 3,880

Fair Value Measurements (Change

Fair Value Measurements (Change in Fair Value for Level 3 Derivatives) (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Fair Value [Abstract]
Beginning balance	$ 3,880	$ (264)
Realized (gains) losses included in earnings	(4,647)	2,765
Unrealized gains (losses) included in AOCIL	2,956	(1,672)
Ending balance	$ 2,189	$ 829

Fair Value Measurements (Fair V

Fair Value Measurements (Fair Value for Level 3 Liabilities) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	$ 47,285	$ 51,826
Contingent consideration recorded at acquisition date	11,669	35
Payment of contingent consideration recorded at acquisition date	(5,459)	(5,840)
Payment of contingent consideration recorded in earnings	(11)
Adjustments to contingent consideration	349	17,754
Reclass earned contingent consideration to accrued liabilities		(20,464)
Interest accretion expense	1,308	1,381
Ending balance	55,024	44,955
Foreign Currency Translation Adjustment [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Foreign currency translation adjustment	$ (117)	$ 263

Other Comprehensive Income (L_3

Other Comprehensive Income (Loss) (Components of Other Comprehensive Income (Loss)) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Components of Other Comprehensive Income (Loss) [Line Items]
Foreign currency translation adjustment, gross	$ 35,455	$ 84,500	$ (67,349)	$ 155,153
Other comprehensive income (loss), gross total	39,082	90,698	(50,805)	158,903
Foreign currency translation adjustment, tax
Income tax (benefit) expense related to items of other comprehensive income loss	(985)	(4,016)	(4,405)	(1,123)
Amounts reclassified, net of tax			(1,721)	3,433
Changes in fair value, net of tax			13,860	(806)
Foreign currency translation adjustment, net	35,455	84,500	(67,349)	155,153
Other comprehensive income (loss), total, net of tax	38,097	86,682	(55,210)	157,780
Interest Rate Swap [Member]
Components of Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified, gross	4,279	511	2,407	2,352
Changes in fair value, gross	863	2,181	15,828	305
Amounts reclassified, tax effect	(1,134)	(135)	(638)	(623)
Changes in fair value, tax effect	(229)	(2,542)	(4,194)	(81)
Amounts reclassified, net of tax	3,145	376	1,769	1,729
Changes in fair value, net of tax	634	(361)	11,634	224
Fuel [Member] | Commodity Contract [Member]
Components of Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified, gross	(1,810)	789	(4,647)	2,765
Changes in fair value, gross	295	2,717	2,956	(1,672)
Amounts reclassified, tax effect	451	(302)	1,157	(1,061)
Changes in fair value, tax effect	(73)	(1,037)	(730)	642
Amounts reclassified, net of tax	(1,359)	487	(3,490)	1,704
Changes in fair value, net of tax	$ 222	$ 1,680	$ 2,226	$ (1,030)

Other Comprehensive Income (L_4

Other Comprehensive Income (Loss) (Amounts Included in Accumulated Other Comprehensive Income (Loss)) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Components of Other Comprehensive Income (Loss) [Line Items]
Beginning balance			$ 108,413	$ (43,001)
Amounts reclassified into earnings			(1,721)	3,433
Changes in fair value			13,860	(806)
Foreign currency translation adjustment	$ 35,455	$ 84,500	(67,349)	155,153
Ending balance	53,203	114,779	53,203	114,779
Interest Rate Swap [Member]
Components of Other Comprehensive Income (Loss) [Line Items]
Beginning balance			13,951	8,094
Amounts reclassified into earnings	3,145	376	1,769	1,729
Changes in fair value	634	(361)	11,634	224
Ending balance	27,354	10,047	27,354	10,047
Foreign Currency Translation Adjustment [Member]
Components of Other Comprehensive Income (Loss) [Line Items]
Beginning balance			91,555	(50,931)
Foreign currency translation adjustment			(67,349)	155,153
Ending balance	24,206	104,222	24,206	104,222
Fuel [Member] | Commodity Contract [Member]
Components of Other Comprehensive Income (Loss) [Line Items]
Beginning balance			2,907	(164)
Amounts reclassified into earnings	(1,359)	487	(3,490)	1,704
Changes in fair value	222	1,680	2,226	(1,030)
Ending balance	$ 1,643	$ 510	$ 1,643	$ 510

Shareholders' Equity (Narrative

Shareholders' Equity (Narrative) (Detail) - USD ($) $ / shares in Units, $ in Thousands	Jul. 24, 2018	Oct. 31, 2017	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Jul. 31, 2018	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of shares authorized for repurchase	13,174,976
Share repurchase plan expiration date	Aug. 7, 2019
Daily repurchase of shares, maximum						71,114
Average daily trading volume during period						284,459
Repurchase of common stock (shares)							594,474	0
Aggregate cost of stock repurchased							$ 42,040
Maximum remaining number of shares available for repurchase				12,587,332			12,587,332		12,587,332
Cash dividend per share		$ 0.14	$ 0.12	$ 0.14	$ 0.12		$ 0.42	$ 0.36
Cash dividend per common share, increase		$ 0.02
Cash dividends on common stock							$ 110,447	$ 95,201
Dividends per share amount				$ 0.14
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant-date fair value of award							$ 69.22
Units granted in period							496,217
Vested deferred RSUs outstanding			352,214	264,374	352,214		264,374	352,214	264,374
Restricted Stock Units (RSUs) [Member] | Progressive Waste Solutions Ltd. [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units granted in period									0
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant-date fair value of award							$ 69.04
Performance period end date							Dec. 31, 2020
Units granted in period							178,377
Performance Shares [Member] | 2018 Performance Based Restricted Share Units Grant One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of award							3 years
Performance Shares [Member] | 2018 Performance Based Restricted Share Units Grant Two [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of award							1 year
Performance Shares [Member] | Progressive Waste Solutions Ltd. [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units granted in period									0
Performance Shares [Member] | Maximum [Member] | 2018 Performance Based Restricted Share Units Grant Two [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of award							4 years
Employee Stock Option [Member] | Progressive Waste Solutions Ltd. [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted in period									0
Deferred Share Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant-date fair value of award							$ 70.47
Units granted in period							4,038
Vested deferred RSUs outstanding				17,176			17,176		17,176	13,138

Shareholders' Equity (Summary o

Shareholders' Equity (Summary of Activity Related to Restricted Stock Units) (Detail)	9 Months Ended
	Sep. 30, 2018shares
Restricted Stock Units (RSUs) [Member]
Unvested shares
Outstanding, shares at December 31, 2017	1,042,014
Granted	496,217
Forfeited	(53,063)
Vested and issued	(480,577)
Vested and deferred	(3,653)
Outstanding at September 30, 2018	264,374
Outstanding, shares at September 30, 2018	1,000,938
Performance Shares [Member]
Unvested shares
Outstanding, shares at December 31, 2017	514,461
Granted	178,377
Forfeited	(2,071)
Vested and issued	(154,181)
Outstanding, shares at September 30, 2018	536,586
Progressive Waste Solutions Ltd. [Member] | Restricted Stock Units (RSUs) [Member]
Unvested shares
Outstanding at December 31, 2017	158,510
Forfeited	(2,435)
Cash settled	(27,059)
Outstanding at September 30, 2018	129,016
Progressive Waste Solutions Ltd. [Member] | Performance Shares [Member]
Unvested shares
Outstanding at December 31, 2017	55,602
Forfeited	(1,909)
Cash settled	(27,033)
Outstanding at September 30, 2018	26,660

Shareholders' Equity (Summary_2

Shareholders' Equity (Summary of Warrant and Deferred Share Unit Activity) (Detail) - Deferred Share Units [Member]	9 Months Ended
	Sep. 30, 2018shares
Warrant
Outstanding at December 31, 2017	13,138
Granted	4,038
Outstanding at September 30, 2018	17,176

Shareholders' Equity (Summary_3

Shareholders' Equity (Summary of Vesting Activity Related to Restricted Share Units) (Details)	9 Months Ended
	Sep. 30, 2018shares
Restricted Stock Units (RSUs) [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Forfeited	(53,063)
Restricted Stock Units (RSUs) [Member] | Progressive Waste Solutions Ltd. [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vested at December 31, 2017	138,054
Vested over remaining service period	14,695
Cash settled	(27,059)
Forfeited	(2,435)
Vested at September 30, 2018	123,255
Performance Shares [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Forfeited	(2,071)
Performance Shares [Member] | Progressive Waste Solutions Ltd. [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vested at December 31, 2017	28,407
Vested over remaining service period	25,417
Cash settled	(27,033)
Forfeited	(1,909)
Vested at September 30, 2018	24,882

Shareholders' Equity (Summary_4

Shareholders' Equity (Summary of Stock Option Activity and Related Information) (Detail) - Progressive Waste Solutions Ltd. [Member]	9 Months Ended
	Sep. 30, 2018shares
Number of Shares (Options)
Outstanding at December 31, 2017	236,616
Cash settled	(71,460)
Outstanding at September 30, 2018	165,156

Commitments and Contingencies (

Commitments and Contingencies (Narrative) (Detail) T in Millions	Aug. 10, 2018USD ($)	Mar. 31, 2018USD ($)	Jul. 31, 2018USD ($)	Jul. 25, 2017USD ($)	Sep. 30, 2018USD ($)	Dec. 31, 2016T	Sep. 30, 2014USD ($)	Jan. 05, 2017USD ($)	Dec. 31, 2014USD ($)
Contingencies And Commitments [Line Items]
Estimated clean up costs									$ 342,000,000
Solid Waste Management Fee Enforcement Order [Member]
Contingencies And Commitments [Line Items]
Loss contingency amount sought							$ 5,100,000
Bridge and Thoroughfare Fee [Member]
Contingencies And Commitments [Line Items]
Loss contingency amount sought		$ 83,000		$ 11,600,000
Noncompliance fee		$ 750
Fee paid	$ 11,600,000
Chiquita Canyon, LLC [Member]
Contingencies And Commitments [Line Items]
Annual tons of waste accepted at landfill | T						3
Estimate of total new fees and other new taxes over the life of the conditional use permit					$ 300,000,000
Environmental Remediation Expense [Member]
Contingencies And Commitments [Line Items]
Estimated period to implement clean-up					seven years
Required period of monitoring following the clean-up					10 years
Penalties and Fees [Member] | Solid Waste Management Fee Enforcement Order [Member]
Contingencies And Commitments [Line Items]
Loss contingency amount sought			$ 5,515,000
Penalties [Member] | Solid Waste Management Fee Enforcement Order [Member]
Contingencies And Commitments [Line Items]
Loss contingency amount sought			$ 3,079,000
Penalties [Member] | Bridge and Thoroughfare Fee [Member]
Contingencies And Commitments [Line Items]
Fee paid	83,000
Fees [Member] | Bridge and Thoroughfare Fee [Member]
Contingencies And Commitments [Line Items]
Fee paid	$ 750
Progressive Waste Solutions Ltd. [Member] | Florida Default Judgment [Member]
Contingencies And Commitments [Line Items]
Estimated loss from final judgment								$ 10,000,000

Subsequent Events (Details)

Subsequent Events (Details) - $ / shares	Oct. 29, 2018	Sep. 30, 2018
Subsequent Event [Line Items]
Dividends per share amount		$ 0.14
Subsequent Event [Member]
Subsequent Event [Line Items]
Dividends, declared date	Oct. 29, 2018
Dividends per share amount	$ 0.16
Increase in regular quarterly cash dividend per share	$ 0.02
Dividends, date to be paid	Nov. 27, 2018
Dividends, date of record	Nov. 13, 2018