Use of Estimates in Preparation of Financial Statements. The preparation of the accompanying Financial Statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of our Financial Statements, and the reported amounts of revenues and expenses during the reporting periods. Actual results could differ from those estimates.

Revenues. The majority of our future revenues is related to our cloud and related solution client contracts that include variable consideration dependent upon a series of monthly volumes and/or daily usage of services and have contractual terms ending from 2019 through 2028. As of June 30, 2019, our aggregate amount of the transaction price allocated to the remaining performance obligations is approximately $501 million, which is made up of fixed fee consideration and guaranteed minimums expected to be recognized in the future related to performance obligations that are unsatisfied (or partially unsatisfied). We expect to recognize approximately 90% of this amount by the end of 2021, with the remaining amount recognized by the end of 2028. We have excluded from this amount variable consideration expected to be recognized in the future related to performance obligations that are unsatisfied.

The nature, amount, timing and uncertainty of our revenues and how revenues and cash flows are affected by economic factors is most appropriately depicted by type of revenues and by geographic region (using the location of the client as the basis of attributing revenues to the individual regions) as follows (in thousands):

	Quarter Ended				Six Months Ended
	June 30,				June 30,
	2019		2018		2019		2018
Cloud and related solutions	$	222,183	$	187,401	$	441,773	$	364,917
Software and services		12,173		13,331		25,201		25,290
Maintenance		11,500		12,301		23,675		24,530
Total revenues	$	245,856	$	213,033	$	490,649	$	414,737

	Quarter Ended				Six Months Ended
	June 30,				June 30,
	2019		2018		2019		2018
Americas (principally the U.S.)	$	214,390	$	180,217	$	425,120	$	350,120
Europe, Middle East, and Africa		22,606		21,977		47,232		42,411
Asia Pacific		8,860		10,839		18,297		22,206
Total revenues	$	245,856	$	213,033	$	490,649	$	414,737

Deferred revenue recognized during the quarter and six months ended June 30, 2019 was $11.3 million and $29.8 million, respectively.

Cash and Cash Equivalents. We consider all highly liquid investments with original maturities of three months or less at the date of the purchase to be cash equivalents. As of June 30, 2019 and December 31, 2018, our cash equivalents consist primarily of institutional money market funds, commercial paper, and time deposits held at major banks.

As of June 30, 2019 and December 31, 2018, we had $3.1 million and $3.0 million, respectively, of restricted cash that serves to collateralize outstanding letters of credit. This restricted cash is included in cash and cash equivalents in our Condensed Consolidated Balance Sheets (“Balance Sheets” or “Balance Sheet”).

Short-term Investments and Other Financial Instruments. Our financial instruments as of June 30, 2019 and December 31, 2018 include cash and cash equivalents, short-term investments, accounts receivable, accounts payable, and debt. Because of their short maturities, the carrying amounts of cash equivalents, accounts receivable, and accounts payable approximate their fair value.

Our short-term investments and certain of our cash equivalents are considered “available-for-sale” and are reported at fair value in our Balance Sheets, with unrealized gains and losses, net of the related income tax effect, excluded from earnings and reported in a separate component of stockholders’ equity. Realized and unrealized gains and losses were not material in any period presented.

Primarily all short-term investments held by us as of June 30, 2019 and December 31, 2018 have contractual maturities of less than two years from the time of acquisition. Our short-term investments as of June 30, 2019 and December 31, 2018 consisted almost entirely of fixed income securities. Proceeds from the sale/maturity of short-term investments for the six months ended June 30, 2019 and 2018 were $28.8 million and $116.9 million, respectively.

Our short-term investments as of June 30, 2019 and December 31, 2018 were $17.7 million and $23.6 million, respectively.

The following table represents the fair value hierarchy based upon three levels of inputs, of which Levels 1 and 2 are considered observable and Level 3 is unobservable, for our financial assets measured at fair value (in thousands):

	June 30, 2019						December 31, 2018
	Level 1		Level 2		Total		Level 1		Level 2		Total
Cash equivalents:
Money market funds	$	4,254	$	—	$	4,254	$	4,392	$	—	$	4,392
Commercial paper		—		10,626		10,626		—		9,078		9,078
Short-term investments:
Corporate debt securities		—		12,834		12,834		—		16,357		16,357
U.S. government agency bonds		—		650		650		—		3,724		3,724
Asset-backed securities		—		4,190		4,190		—		3,522		3,522
Total	$	4,254	$	28,300	$	32,554	$	4,392	$	32,681	$	37,073

Valuation inputs used to measure the fair values of our money market funds and corporate equity securities were derived from quoted market prices. The fair values of all other financial instruments are based upon pricing provided by third-party pricing services. These prices were derived from observable market inputs.

We have chosen not to measure our debt at fair value, with changes recognized in earnings each reporting period. The following table indicates the carrying value (par value for convertible debt) and estimated fair value of our debt as of the indicated periods (in thousands):

	June 30, 2019				December 31, 2018
	Carrying		Fair		Carrying		Fair
	Value		Value		Value		Value
2018 Credit Agreement (carrying value including current maturities)	$	140,625	$	140,625	$	144,375	$	144,375
2016 Convertible debt (par value)		230,000		254,438		230,000		228,275

The fair value for our credit agreement was estimated using a discounted cash flow methodology, while the fair value for our convertible debt was estimated based upon quoted market prices or recent sales activity, both of which are considered Level 2 inputs.

Equity Method Investment. During the six months ended June 30, 2019, we made an additional $4 million investment in a payment technology and services company that enables omni-channel digital payments in Latin America. As of June 30, 2019, we held an 8% noncontrolling interest with a carrying value of $6.7 million.

Accounting Pronouncements Adopted. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842). This ASU requires lessees to recognize a right-of-use asset and lease liability for all leases, including operating leases, with a term greater than twelve months on its balance sheet. This ASU is effective for annual and interim periods beginning after December 31, 2018. An entity is required to use a modified retrospective transition approach, but may choose to use either the effective date or the beginning of the earliest comparative period presented in its financial statements as of the date of initial application.

We adopted this ASU in January 2019, utilizing the effective date method of transition. Since we adopted this ASU utilizing the effective date method, prior period information in our Financial Statements has not been adjusted and continues to be as previously reported. We elected the package of practical expedients permitted under the transition guidance within the new standard. Additionally, we updated our polices to align with the new accounting guidance and our processes to ensure that we properly account for new, existing, and modifications to leases subsequent to the adoption of the ASU. In conjunction with the adoption of this ASU we recorded additional assets and liabilities of approximately $80 million related to the right-of-use assets and lease liabilities, and have included the amortization of the right-of-use-assets and the accretion and payments of lease liabilities in the changes in other current and non-current assets and liabilities and in the changes in trade accounts payable and accrued liabilities, respectively, on our Statement of Cash Flows.