
	Revenue from Contracts with Customers

Disaggregation of Revenue

The following table provides information about disaggregated revenue by type of product and contract for the three and six months ended June 30, 2019 and 2018:



	For the Three Months Ended June 30,				For the Six Months Ended June 30,
	2019		2018		2019		2018
	(Dollars in thousands)
Graphite Electrodes - Three-to-five-year take-or-pay contracts	$	377,605	$	345,246	$	773,645	$	617,447
Graphite Electrodes - Short-term agreements and spot sales	76,249		66,764		123,545		210,474
By-products and other	26,536		44,322		58,194		80,310
Total Revenues	$	480,390	$	456,332	$	955,384	$	908,231

Effective the first quarter of 2019, the Graphite Electrodes revenue categories include only graphite electrodes manufactured by GrafTech. The revenue category “By-products and Other” now includes re-sales of low-grade electrodes purchased from third party suppliers, which represent a minimal contribution to our profitability. For comparability purposes, the prior period has been recast to conform to this presentation.

Contract Balances

Receivables, net of allowances for doubtful accounts, were $313.6 million as of June 30, 2019 and $248.3 million as of December 31, 2018. Accounts receivables are recorded when the right to consideration becomes unconditional. Payment terms on invoices range from 30 to 120 days depending on the customary business practices of the jurisdictions in which we do business.

Certain short-term and longer-term sales contracts require up-front payments prior to the Company’s fulfillment of any performance obligation. These contract liabilities are recorded as current or long-term deferred revenue, depending on the lag between the pre-payment and the expected delivery of the related products. Additionally, under ASC 606, deferred revenue originates from contracts where the allocation of the transaction price to the performance obligations based on their relative stand-alone selling prices results in the timing of revenue recognition being different from the timing of the invoicing. In this case, deferred revenue is amortized into revenue based on the transaction price allocated to the remaining performance obligations.

Current deferred revenue is included in "Other accrued liabilities" and long-term deferred revenue is included in "Other long-term obligations" on the Condensed Consolidated Balance Sheets.

The following table provides information about deferred revenue from contracts with customers (in thousands):



	Current deferred revenue			Long-Term deferred revenue
	(dollars in thousands)
Balance as of December 31, 2018	$	5,380		$	7,716
Revenue recognized that was included in the deferred revenue balance at the beginning of the period	(1,643		)	—
Increases due to cash received, excluding amounts recognized as revenue during the period	910			—
Foreign currency impact	4			36
Balance as of June 30, 2019	$	4,651		$	7,752

Transaction Price Allocated to the Remaining Performance Obligations

The following table presents estimated revenues expected to be recognized in the future related to performance obligations that are unsatisfied (or partially unsatisfied) at the end of the reporting period. The estimated revenues do not include contracts with original duration of one year or less.



	Three-to-five-year take-or-pay contracts
	(dollars in thousands)
Remainder of 2019	692,358
2020	1,392,966
2021	1,237,952
2022	1,172,028
Thereafter	29,461
Total	$	4,524,765

In addition to the expected remaining revenue to be recognized with the longer-term sales contracts, the Company recorded $773.6 million of revenue pursuant to these contracts in the six months ended June 30, 2019.