Residential and business subscription services revenue consists primarily of monthly recurring charges for HSD, Video, and Telephony services, including charges for equipment rentals and other regulatory fees, and non-recurring charges for optional services, such as pay-per-view, video-on-demand, and other events provided to the customer. Monthly charges for residential and business subscription services are billed in advance and recognized as revenue over the period of time the associated services are provided to the customer. Charges for optional services are generally billed in arrears and revenue is recognized at the point in time when the services are provided to the customer.

While a portion of residential customers have entered into contracts for subscription services ranging from 12 months to 24 months in length, the Company recognizes revenue for these customers on a basis that is consistent with customers that have entered into month-to-month contracts as the early termination fees within these contracts are not considered to be material. The Company’s business customers have entered into non-cancellable contracts for subscription services averaging 30 months.

The Company is required to pay certain cable franchising authorities an amount based on the percentage of gross revenue derived from video services. The Company generally passes these fees and other similar regulatory and ancillary fees on to the customer. Revenues from regulatory and other ancillary fees passed on to the customer are reported with the associated service revenue and the corresponding costs are reported as an operating expense.

Bundled Subscription Services

The Company often markets multiple subscription services as part of a bundled arrangement that may include a discount. When customers have entered into a bundled service arrangement, the total transaction price for the bundled arrangement is allocated between the separate services included in the bundle based on their relative stand-alone selling prices. The allocation of the transaction price in bundled services requires judgment, particularly in determining the stand-alone selling prices for the separate services included in the bundle. The stand-alone selling price for the majority of services are determined based on the prices at which the Company separately sells the service. For services sold on an infrequent basis and for a wide range of prices, the Company estimates stand-alone selling prices using the adjusted market assessment approach, which considers the prices of competitors for similar services.

Other Business Services Revenue

Other business services revenue consists primarily of monthly recurring charges for session initiated protocol, web hosting, metro ethernet, wireless backhaul, broadband carrier, and cloud infrastructure services provided to business customers. Other business services revenue also includes recurring charges for wholesale and colocation services. Monthly charges for other business services are generally billed in advance and recognized as revenue when the associated services are provided to the customer.

Other Revenue

Other revenue consists primarily of revenue from line assurance warranty services provided to residential and business customers and revenue from advertising placement. Monthly charges for line assurance warranty services are generally billed in advance and recognized as revenue over the period of time the warranty services are provided to the customer. Charges for advertising placement are generally billed in arrears and recognized as revenue at the point in time when the advertising is distributed.

Revenue by Service Offering

The following table presents revenue by service offering for the years ended December 31, 2020, 2019 and 2018, respectively:


	Year ended December 31,
	2020		2019		2018

	(in millions)
Residential subscription
HSD	$	480.1	$	440.7	$	393.6
Video		393.8		417.4		465.3
Telephony		52.5		59.9		74.4
Total Residential subscription	$	926.4	$	918.0	$	933.3
Business subscription
HSD	$	87.1	$	80.3	$	73.5
Video		15.0		14.6		14.1
Telephony		41.6		42.8		41.9
Total business subscription	$	143.7	$	137.7	$	129.5
Total subscription services revenue		1,070.1		1,055.7		1,062.8
Other business services revenue(1)		25.3		27.4		28.1
Other revenue		53.0		62.7		62.9
Total revenue	$	1,148.4	$	1,145.8	$	1,153.8

(1)	Includes wholesale and colocation revenue of $21.3 million, $21.6 million and $21.9 million for the years ended December 31, 2020, 2019 and 2018, respectively.

Costs of Obtaining Contracts with Customers

The Company recognizes an asset for incremental costs of obtaining contracts with customers when it expects to recover those costs. Costs which would be incurred regardless of whether a contract is obtained are expensed as they are incurred. Costs of obtaining contracts with customers are amortized over the expected period of benefit, which generally ranges from three to four years for residential customers and six to seven years for business customers. The current portion and the non-current portion of costs of obtaining contracts with customers are included in prepaid expenses and other and other noncurrent assets, respectively, in the Company’s consolidated balance sheets. Amortization of costs of obtaining contracts with customers is included in selling, general and administrative expense in the Company’s consolidated statements of operations.

The following table summarizes the activity of costs of obtaining contracts with customers:


	2020		2019		2018

	(in millions)
Balance at beginning of period	$	40.7	$	26.3	$	—
Impact of change in accounting policy		—		—		11.4
Deferral		21.1		22.2		19.0
Amortization		(12.2)		(7.8)		(4.1)
Balance at end of period	$	49.6	$	40.7	$	26.3

The following table presents the current and non-current costs of obtaining contracts with customers as of the end of the corresponding periods:


	December 31, 2020		December 31, 2019

	(in millions)
Current costs of obtaining contracts with customers	$	15.3	$	10.0
Non-current costs of obtaining contracts with customers		34.3		30.7
Total costs of obtaining contracts with customers	$	49.6	$	40.7

Contract Liabilities

Monthly charges for residential and business subscription services are billed in advance and recorded as unearned service revenue. Residential and business customers may be charged non-recurring upfront fees associated with installation and other administrative activities. Charges for upfront fees associated with installation and other administrative activities are initially recorded as unearned service revenue and recognized as revenue over the expected period of benefit for residential customers, which has been estimated as five months, and over the contract term for business customers, which has been estimated as thirty months. The Company has estimated the expected period of benefit for residential customers based on consideration of quantitative and qualitative factors including the average installation fee charged, the average monthly revenue per customer, and customer behavior. The current portion and the non-current portion of contract liabilities are included in current portion of unearned service revenue and other non-current liabilities, respectively, in the Company’s consolidated balance sheets.

The following tables present the activity of current and non-current contract liabilities:


	2020		2019		2018

	(in millions)
Balance at beginning of period	$	4.2	$	3.9	$	—
Impact of change in accounting policy		—		—		2.1
Deferral		14.3		16.1		17.5
Revenue recognized		(14.3)		(15.8)		(15.7)
Balance at end of period	$	4.2	$	4.2	$	3.9

The following table presents the current and non-current portion of contract liabilities as of the end of the corresponding periods:


	December 31, 2020		December 31, 2019

	(in millions)
Current contract liabilities	$	3.6	$	3.6
Non-current contract liabilities		0.6		0.6
Total contract liabilities	$	4.2	$	4.2

Unsatisfied Performance Obligations

Revenue from month-to-month residential subscription service contracts have historically represented a significant portion of the Company’s revenue and the Company expects that this will continue to be the case in future periods. All residential subscription service performance obligations will be satisfied within one year.

A summary of expected business subscription and other business services revenue to be recognized in future periods related to performance obligations which have not been satisfied or are partially unsatisfied as of December 31, 2020 is set forth in the table below:


	2021		2022		2023		Thereafter		Total

	(in millions)
Subscription services	$	68.9	$	35.7	$	11.6	$	7.1	$	123.3
Other business services		3.5		1.7		0.4		—		5.6
Total expected revenue	$	72.4	$	37.4	$	12.0	$	7.1	$	128.9

Provision for Doubtful Accounts

The provision for doubtful accounts and allowance for doubtful accounts are based on the aging of the individual receivables, historical trends and current and anticipated future economic conditions. The Company manages credit risk by disconnecting services to customers who are delinquent, generally after sixty days of delinquency. From March 12, 2020 through June 30, 2020, the Company suspended certain collection activities as a result of participation in the Federal Communications Commission (“FCC”) Keep Americans Connected Pledge. The FCC Pledge expired on June 30, 2020, however the Company continued to arrange payment plans for those customers impacted by COVID-19 through December 31, 2020. Individual receivables are written-off after all reasonable efforts to collect the funds have been made. Actual write-offs may differ from the amounts reserved.

The following table presents the change in the allowance for doubtful accounts for trade accounts receivable:


	Year ended
	December 31,
	2020		2019

	(in millions)
Balance at beginning of period	$	7.5	$	7.5
Provision charged to expense		16.4		16.9
Accounts written off, net of recoveries		(15.3)		(16.9)
Balance at end of period	$	8.6	$	7.5

The Company had accounts written off, net of recoveries, of non-trade accounts receivable of $0.4 million for the year ended December 31, 2020. The Company did not have such write-offs for the year ended December 31, 2019.