Note 11. Deferred Revenue and Performance Obligations

For subscription and services revenue, the Company typically invoices in advance of providing services. Deferred revenue represents the unearned revenue on cash receipts or accounts receivable for the sale of subscriptions and professional services for which services have not yet been provided. In the case where amounts are not collected, but the service has been provided and the revenue has been recognized, the amounts are recorded in accounts receivable. The opening and ending balances of the Company’s deferred revenue are as follows:

	Three Months Ended March 31, 2018
	Subscription			Services			Total
Deferred revenue balance, beginning of period	$	110,934		$	8,367		$	119,301
Revenue recognized during the period		(45,471	)		(8,015	)		(53,486	)
Additions to deferred revenue during the period, including deferred revenue acquired		48,407			9,222			57,629
Deferred revenue balance, end of period	$	113,870		$	9,574		$	123,444

During the three months ended March 31, 2018 and 2017, $38.7 million and $32.6 million of subscription revenue was recognized, respectively, that was included in the deferred revenue balances at the beginning of the respective periods. $2.7 million and $2.3 million of professional services revenue was recognized during the three months ended March 31, 2018 and 2017, respectively, that was included in the deferred revenue balances at the beginning of the respective periods.

Transaction Price Allocated to the Remaining Performance Obligations

As of March 31, 2018, approximately $217.1 million of subscription revenue is expected to be recognized from remaining performance obligations for subscription contracts. The Company expects to recognize revenue on approximately 90% of these remaining performance obligations over the next 24 months, with the balance recognized thereafter. As of March 31, 2018, approximately $12.3 million of services revenue is expected to be recognized from remaining performance obligations for service contracts. The Company will recognize the remaining performance obligations for services revenue as services are performed.