In the following table, revenue is disaggregated by type of service and timing of revenue recognition. Service revenues are recognized over time and Equipment sales are point in time.



			TDS Telecom
Three Months Ended September 30, 2019	U.S. Cellular		Wireline		Cable		TDS Telecom Total¹		Corporate, Eliminations and Other		Total
(Dollars in millions)
Revenues from contracts with customers:
Type of service:
Retail service	$	663	$	—	$	—	$	—	$	—	$	663
Inbound roaming	54		—		—		—		—		54
Residential	—		83		52		135		—		135
Commercial	—		41		10		52		—		52
Wholesale	—		44		—		44		—		44
Other service	34		—		—		—		19		53
Service revenues from contracts with customers	751		168		62		230		19		1,001
Equipment and product sales	257		—		—		—		34		291
Total revenues from contracts with customers²	$	1,008	$	168	$	62	$	230	$	53	$	1,292



			TDS Telecom
Three Months Ended September 30, 2018	U.S. Cellular		Wireline		Cable		TDS Telecom Total¹		Corporate, Eliminations and Other		Total
(Dollars in millions)
Revenues from contracts with customers:
Type of service:
Retail service	$	659	$	—	$	—	$	—	$	—	$	659
Inbound roaming	50		—		—		—		—		50
Residential	—		81		47		128		—		128
Commercial	—		46		10		56		—		56
Wholesale	—		50		—		50		—		50
Other service	34		—		—		—		18		52
Service revenues from contracts with customers	743		176		58		233		18		995
Equipment and product sales	242		—		—		—		38		280
Total revenues from contracts with customers²	$	985	$	176	$	58	$	234	$	56	$	1,275



			TDS Telecom
Nine Months Ended September 30, 2019	U.S. Cellular		Wireline		Cable		TDS Telecom Total¹			Corporate, Eliminations and Other		Total
(Dollars in millions)
Revenues from contracts with customers:
Type of service:
Retail service	$	1,984	$	—	$	—	$	—		$	—	$	1,984
Inbound roaming	132		—		—		—			—		132
Residential	—		245		152		397			—		397
Commercial	—		127		32		159			—		159
Wholesale	—		137		—		137			—		137
Other service	101		—		—		(1		)	54		154
Service revenues from contracts with customers	2,217		510		183		692			54		2,963
Equipment and product sales	698		1		—		1			103		802
Total revenues from contracts with customers²	$	2,915	$	511	$	184	$	693		$	157	$	3,765



			TDS Telecom
Nine Months Ended September 30, 2018	U.S. Cellular		Wireline		Cable		TDS Telecom Total¹			Corporate, Eliminations and Other		Total
(Dollars in millions)
Revenues from contracts with customers:
Type of service:
Retail service	$	1,960	$	—	$	—	$	—		$	—	$	1,960
Inbound roaming	116		—		—		—			—		116
Residential	—		241		140		381			—		381
Commercial	—		140		30		170			—		170
Wholesale	—		143		—		143			—		143
Other service	99		—		—		(1		)	52		150
Service revenues from contracts with customers	2,175		524		170		693			52		2,920
Equipment and product sales	692		1		—		1			96		789
Total revenues from contracts with customers²	$	2,867	$	525	$	170	$	694		$	148	$	3,709



	September 30, 2019		December 31, 2018
(Dollars in millions)
Accounts receivable
Customer and agents	$	984	$	987
Other	107		73
Total¹	$	1,091	$	1,060

The following table provides a rollforward of contract assets from contracts with customers, which are recorded in Other current assets and Other assets and deferred charges in the Consolidated Balance Sheet.



	Contract Assets
(Dollars in millions)
Balance at December 31, 2018	$	11
Contract additions	11
Reclassified to receivables	(12		)
Balance at September 30, 2019	$	10

The following table provides a rollforward of contract liabilities from contracts with customers, which are recorded in Customer deposits and deferred revenues and Other deferred liabilities and credits in the Consolidated Balance Sheet.



	Contract Liabilities
(Dollars in millions)
Balance at December 31, 2018¹	$	187
Contract additions	117
Terminated contracts	(6		)
Revenue recognized	(98		)
Balance at September 30, 2019	$	200

The following table includes estimated service revenues expected to be recognized related to performance obligations that are unsatisfied (or partially unsatisfied) at the end of the reporting period. These estimates represent service revenues to be recognized when services are delivered to customers pursuant to service plan contracts and under certain roaming agreements with other carriers. These estimates are based on contracts in place as of September 30, 2019, and may vary from actual results. As a practical expedient, revenue related to contracts of less than one year, generally month-to-month contracts, are excluded from these estimates.

TDS has certain contracts at U.S. Cellular and TDS Telecom in which it bills an amount equal to a fixed per-unit price multiplied by a variable quantity (e.g., certain roaming agreements with other carriers). Because TDS invoices for such items in an amount that corresponds directly with the value of the performance completed to date, TDS may recognize revenue in that amount. As a practical expedient, these contracts are excluded from the estimate of future revenues expected to be recognized related to performance obligations that are unsatisfied as of the end of a reporting period.

TDS expects that incremental commission fees paid as a result of obtaining contracts are recoverable and therefore TDS capitalizes these costs. As a practical expedient, costs with an amortization period of one year or less are not capitalized. TDS also incurs fulfillment costs, such as installation costs, where there is an expectation that a future benefit will be realized. Capitalized commission fees and fulfillment costs are amortized based on the timing of transfer of the goods or services to which the assets relate, typically the contract term which ranges from fifteen months to thirty-nine months. Contract cost asset balances, which are recorded in Other assets and deferred charges in the Consolidated Balance Sheet, were as follows:



	September 30, 2019		December 31, 2018
(Dollars in millions)
Costs to obtain contracts
Sales commissions	$	144	$	154
Fulfillment costs
Installation costs	11		10
Total contract cost assets	$	155	$	164

Amortization of contract cost assets was $31 million and $95 million for the three and nine months ended September 30, 2019, respectively, and $31 million and $93 million for the three and nine months ended September 30, 2018, respectively, and was included in Selling, general and administrative expenses.