Revenue recognition (Tables)

3 Months Ended

Mar. 31, 2019

Revenue from Contract with Customer [Abstract]

The following table reflects the change in contract liabilities between December 31, 2018 and March 31, 2019.



	Contract liabilities
Balance at December 31, 2018	$	49,862
Revenue recognized that was included in the contract liability at the beginning of the year	(11,678		)
Increase, excluding amounts recognized as revenue during the period	15,388
Balance at March 31, 2019	$	53,572

Remaining Performance Obligation

The following table illustrates estimated revenues expected to be recognized in the future related to performance obligations that are unsatisfied (or partially unsatisfied) as of March 31, 2019. The Company has elected to exclude short term contracts, sales and usage based royalties and any other variable consideration recognized on an "as invoiced" basis.



Contract liabilities to be recognized in:	Amount
Remainder of 2019	$	23,208
2020	5,026
2021	2,674
2022	2,559
2023	2,479
Thereafter	17,626
Total	$	53,572