In connection with our investing and operating activities, we have entered into certain contractual obligations and commitments. See Notes 8 and 14 to these consolidated financial statements for additional discussion of these obligations and commitments. Our future minimum cash payments, including interest, associated with our contractual obligations pursuant to the note purchase agreements, Credit Agreement, Premium Financing Debt Facility, operating leases and purchase commitments at December 31, 2020 were as follows (in millions):

	Payments Due by Period
Contractual Obligations	2021			2022			2023			2024			2025			Thereafter			Total
Note purchase agreements	$	75.0		$	200.0		$	250.0		$	475.0		$	200.0		$	3,148.0		$	4,348.0
Credit Agreement		—			—			—			—			—			—			—
Premium Financing Debt Facility		203.6			—			—			—			—			—			203.6
Interest on debt		189.5			183.6			174.7			158.0			143.4			601.9			1,451.1
Total debt obligations		468.1			383.6			424.7			633.0			343.4			3,749.9			6,002.7
Operating lease obligations		108.5			93.9			75.1			54.8			41.6			77.8			451.7
Less sublease arrangements		(0.3	)		(0.3	)		(0.2	)		(0.2	)		(0.2	)		(0.5	)		(1.7	)
Outstanding purchase obligations		75.3			49.4			30.8			21.9			16.7			22.7			216.8
Total contractual obligations	$	651.6		$	526.6		$	530.4		$	709.5		$	401.5		$	3,849.9		$	6,669.5

The amounts presented in the table above may not necessarily reflect our actual future cash funding requirements, because the actual timing of the future payments made may vary from the stated contractual obligation. As of December 31, 2020, we had a $48.2 million accrued liability related to the Ashton Tiffany acquisition that is not in the foregoing table that may be settled using shares of our common stock in early February 2021.

On December 23, 2020, we signed a definitive agreement to acquire 100% of the equity of The Bollington Wilson Group (which we refer to as Bollington) headquartered in Sale, Greater Manchester, U.K., for approximately $330.0 million of cash consideration. The transaction is subject to regulatory approval, which was received on January 26, 2021, and is expected to close in February 2021.

Note Purchase Agreements, Credit Agreement and Premium Financing Debt Facility - See Note 8 to these consolidated financial statements for a summary the amounts outstanding under the note purchase agreements, the Credit Agreement and Premium Debt Facility.

Operating Lease Obligations - Our corporate segment’s executive offices and certain subsidiary and branch facilities of our brokerage and risk management segments are located in a building we own at 2850 Golf Road, Rolling Meadows, Illinois, where we have approximately 360,000 square feet of space and will accommodate approximately 2,000 employees at peak pre-pandemic capacity. During first quarter 2017, we relocated our corporate office headquarters to the Rolling Meadows location. Relating to the development of our corporate headquarters, we expect to receive property tax related credits under a tax-increment financing note from Rolling Meadows and an Illinois state Economic Development for a Growing Economy (which we refer to as EDGE) tax credit. Incentives from these two programs could total between $60.0 million and $90.0 million over a fifteen-year period. We have earned approximately $25.5 million of EDGE credits from inception through December 31, 2020.

We generally operate in leased premises at our other locations. Certain of these leases have options permitting renewals for additional periods. In addition to minimum fixed rentals, a number of leases contain annual escalation clauses which are generally related to increases in an inflation index.

Total rent expense, including rent relating to cancelable leases and leases with initial terms of less than one year, amounted to $154.0 million in 2020, $148.1 million in 2019 and $140.0 million in 2018.

We have leased certain office space to several non-affiliated tenants under operating sublease arrangements. In the normal course of business, we expect that certain of these leases will not be renewed or replaced. We adjust charges for real estate taxes and common area maintenance annually based on actual expenses, and we recognize the related revenues in the year in which the expenses are incurred. These amounts are not included in the minimum future rentals to be received in the contractual obligations table above.

Outstanding Purchase Obligations - We typically do not have a material amount of outstanding purchase obligations at any point in time. The amount disclosed in the contractual obligations table above represents the aggregate amount of unrecorded purchase obligations that we had outstanding at December 31, 2020. These obligations represent agreements to purchase goods or services that were executed in the normal course of business.

Off-Balance Sheet Commitments - Our total unrecorded commitments associated with outstanding letters of credit, financial guarantees and funding commitments at December 31, 2020 were as follows (in millions):

	Amount of Commitment Expiration by Period
Off-Balance Sheet Commitments	2021		2022		2023		2024		2025		Thereafter		Total Amounts Committed
Letters of credit	$	—	$	—	$	—	$	—	$	—	$	18.4	$	18.4
Financial guarantees		0.2		0.2		0.2		0.2		0.2		0.2		1.2
Total commitments	$	0.2	$	0.2	$	0.2	$	0.2	$	0.2	$	18.6	$	19.6

Since commitments may expire unused, the amounts presented in the table above do not necessarily reflect our actual future cash funding requirements. See Note 14 to these consolidated financial statements for a discussion of our funding commitments related to our corporate segment and the Off-Balance Sheet Debt section below for a discussion of other letters of credit. All of the letters of credit represent multiple year commitments that have annual, automatic renewing provisions and are classified by the latest commitment date.

Since January 1, 2002, we have acquired 583 companies, all of which were accounted for using the acquisition method for recording business combinations. Substantially all of the purchase agreements related to these acquisitions contain provisions for potential earnout obligations. For all of our acquisitions made in the period from 2016 to 2020 that contain potential earnout obligations, such obligations are measured at fair value as of the acquisition date and are included on that basis in the recorded purchase price consideration for the respective acquisition. The amounts recorded as earnout payables are primarily based upon estimated future potential operating results of the acquired entities over a two- to three-year period subsequent to the acquisition date. The aggregate amount of the maximum earnout obligations related to these acquisitions was $1,128.1 million, of which $592.2 million was recorded in our consolidated balance sheet as of December 31, 2020 based on the estimated fair value of the expected future payments to be made, of which approximately $493.7 million can be settled in cash or stock at our option and $98.5 million must be settled in cash.

Off-Balance Sheet Debt - Our unconsolidated investment portfolio includes investments in enterprises where our ownership interest is between 1% and 50%, in which management has determined that our level of influence and economic interest is not sufficient to require consolidation. As a result, these investments are accounted for under the equity method. None of these unconsolidated investments had any outstanding debt at December 31, 2020 and 2019 that was recourse to us.

At December 31, 2020, we had posted two letters of credit totaling $9.4 million in the aggregate, related to our self-insurance deductibles, for which we had a recorded liability of $17.5 million. We have an equity investment in a rent-a-captive facility, which we use as a placement facility for certain of our insurance brokerage operations. At December 31, 2020, we had posted seven letters of credit totaling $7.5 million to allow certain of our captive operations to meet minimum statutory surplus requirements plus additional collateral related to premium and claim funds held in a fiduciary capacity, one letter of credit totaling $1.0 million for collateral related to claim funds held in a fiduciary capacity by a recent acquisition, and one letter of credit totaling $0.5 million as a security deposit for a 2015 acquisition’s lease. These letters of credit have never been drawn upon.

Our commitments associated with outstanding letters of credit, financial guarantees and funding commitments at December 31, 2020 were as follows (all dollar amounts in table are in millions):

Description, Purpose and Trigger	Collateral	Compensation to Us	Maximum Exposure		Liability Recorded
Credit support under letters of credit (LOC) for deductibles due by us on our own insurance coverages - expires after 2025	None	None	$	9.4	$	17.5
Trigger - We do not reimburse the insurance companies for deductibles the insurance companies advance on our behalf
Credit enhancement under letters of credit for our captive insurance operations to meet minimum statutory capital requirements - expires after 2025	None	Reimbursement of LOC fees		7.5		-
Trigger - Dissolution or catastrophic financial results of the operation
Collateral related to claims funds held in a fiduciary capacity by a recent acquisition - expires 2021	None	None		1.0		-
Trigger - Claim payments are not made
Credit support under letters of credit in lieu of a security deposit for an acquisition's lease - expires after 2025	None	None		0.5		-
Trigger - Lease payments do not get made
Financial guarantees of loans to 5 Canadian-based employees - expires when loan balances are reduced to zero through May 2029 - Principal and interest payments are paid quarterly	(1)	None		1.2		-
Trigger - Default on loan payments
			$	19.6	$	17.5

Since commitments may expire unused, the amounts presented in the table above do not necessarily reflect our actual future cash funding requirements.

Litigation, Regulatory and Taxation Matters - We are a defendant in various legal actions incidental to the nature of our business including but not limited to matters related to employment practices, alleged breaches of non-compete or other restrictive covenants, theft of trade secrets, breaches of fiduciary duties and related causes of action. We are also periodically the subject of inquiries, investigations and reviews by regulatory and taxing authorities into various matters related to our business, including our operational, compliance and finance functions. Neither the outcomes of these matters nor their effect upon our business, financial condition or results of operations can be determined at this time.

On July 17, 2019, Midwest Energy Emissions Corp. and MES Inc. (which we refer to together as Midwest Energy) filed a patent infringement lawsuit in the United States District Court for the District of Delaware against us, Chem‑Mod LLC and numerous other related and unrelated parties. The complaint alleges that the named defendants infringe patents held exclusively by Midwest Energy and seeks unspecified damages and injunctive relief. On July 15, 2020, the district court dismissed Midwest Energy’s complaint without prejudice. On the same day, Midwest Energy filed an amended complaint. We filed a motion to dismiss the amended complaint, and Midwest Energy subsequently filed a second amended complaint, which we again have moved to dismiss. We continue to defend this matter vigorously. Litigation is inherently uncertain and it is not possible for us to predict the ultimate outcome of this matter and the financial impact to us. We believe the probability of a material loss is remote.

As previously disclosed, our IRC 831(b) (or “micro-captive”) advisory services businesses has been under investigation by the IRS since 2013. Among other matters, the IRS is investigating whether we have been acting as a tax shelter promotor in connection with these operations. Additionally, the IRS has initiated audits for the 2012 tax year, and subsequent tax years, of over 100 of the micro-captive underwriting enterprises organized and/or managed by us.

In May 2020 we learned that the DOJ is conducting a criminal investigation related to IRC 831(b) micro-captive underwriting enterprises. We have been advised that we are not currently a target of the investigation. In June 2020 our subsidiary Artex Risk Solutions, Inc. (which we refer to as Artex) received a grand jury subpoena requesting documents relating to its micro-captive advisory business. We have produced documents in response to the subpoena. We are fully cooperating with both the IRS investigation and the DOJ investigation. We are not able to reasonably estimate the amount of any potential loss in connection with these investigations.

On December 7, 2018, a class action lawsuit was filed against us, Artex and other defendants in the United States District Court for the District of Arizona. The named plaintiffs are micro-captives and related entities and owners who had IRS Section 831(b) tax benefits disallowed by the IRS. The complaint alleges that the defendants defrauded the plaintiffs by marketing and managing micro‑captives with the knowledge that the captives did not constitute bona fide insurance and thus would not qualify for tax benefits. The complaint does not specify the amount of damages sought by the named plaintiffs. On August 5, 2019, the trial court granted the defendants’ motion to compel arbitration and dismissed the class action lawsuit. Plaintiffs appealed this ruling to the United States Court of Appeals for the Ninth Circuit. On September 9, 2020, the Ninth Circuit Court affirmed the ruling of the trial court dismissing the class action lawsuit. We will continue to defend against the lawsuit vigorously. Litigation is inherently uncertain, however, and it is not possible for us to predict the ultimate outcome of this matter and the financial impact to us, nor are we able to reasonably estimate the amount of any potential loss in connection with this lawsuit.

Contingent Liabilities - We purchase insurance to provide protection from errors and omissions (which we refer to as E&O) claims that may arise during the ordinary course of business. Currently we retain the first $10.0 million of every E&O claim up to $10.0 million. In addition, we retain, in aggregate: up to another $4.5 million between $10.0 million and $100.0 million, plus up to another $20.0 million between $100.0 million and $240.0 million, and up to another $27.0 million between $240.0 million and 350.0 million. We have historically maintained self-insurance reserves for the portion of our E&O exposure that is not insured. We periodically determine a range of possible reserve levels using actuarial techniques that rely heavily on projecting historical claim data into the future. Our E&O reserve in the December 31, 2020 consolidated balance sheet is above the lower end of the most recently determined actuarial range by $2.6 million and below the upper end of the actuarial range by $6.4 million. In addition to this E&O reserve, in 2020, we established provisions for potential unusual pandemic related claim defense and other costs. We can make no assurances that the historical claim data used to project the current reserve levels will be indicative of future claim activity. Thus, the E&O reserve level and corresponding actuarial range could change in the future as more information becomes known, which could materially impact the amounts reported and disclosed herein.

Tax-advantaged Investments No Longer Held - Between 1996 and 2007, we developed and then sold portions of our ownership in various energy related investments, many of which qualified for tax credits under IRC Section 29. We recorded tax benefits in connection with our ownership in these investments. At December 31, 2020, we had exposure on $108.0 million of previously earned tax credits. Under the TCJA, a portion of these previously earned tax credits were refunded in 2019 for tax year 2018, according to a specific formula. Under the Coronavirus Act, Relief, and Economic Security Act (the CARES Act), which was passed on March 27, 2020, we accelerated the refund of all remaining credits on April 17, 2020, and the remaining credits were refunded to us in the second quarter of 2020. In 2004, 2007 and 2009, the IRS examined several of these investments and all examinations were closed without any changes being proposed by the IRS. However, any future adverse tax audits, administrative rulings or judicial decisions could disallow previously claimed tax credits.

Due to the contingent nature of this exposure and our related assessment of its likelihood, no reserve has been recorded in our December 31, 2020 consolidated balance sheet related to this exposure.