v3.19.1

Contract assets and contract liabilities (Tables) | 3 Months Ended
--- | ---
Mar. 31, 2019
Contract assets and contract liabilities |
Schedule of contract asset, net and contract liability, net balance from customers and performance obligations included in revenues | The opening and closing balances of our contract asset, net, contract liability, net, and receivables balances from contracts with customers for the three months ended March 31, 2019 are as follows:
|  | Contract |  | Contract
|  | assets, net |  | liabilities, net
Balance at December 31, 2018 |  | $ | 468 |  | $ | 217,733
Balance at March 31, 2019 |  |  | 1,117 |  |  | 218,029
Change |  | $ | 649 |  | $ | 296
Revenues for the three months ended March 31, 2019 include the following:
|  |  | Three Months Ended
|  | March 31, 2019
Amounts included in the beginning of period contract liability balance |  | $ | 28,871
Amounts associated with performance obligations satisfied in previous periods |  |  | 294

X
- Definition Tabular disclosure of contract balances and changes in contract balances. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130551-203045 + Details
Name: | us-gaap_ContractWithCustomerAssetAndLiabilityTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_RevenueFromContractWithCustomerAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration