Revenue - Contract balances (Details) - USD ($) $ in Thousands		9 Months Ended
Jan. 01, 2018	Sep. 30, 2018
Contract balances
Receivables, inclusive of trade and unbilled	$ 48,217	$ 42,534
Contract Assets (current and non-current)	8,167	11,060
Contract Liabilities (Deferred Revenue current and non-current)	$ 33,752	$ 33,598
Revenue, Practical Expedient, Financing Component [true/false]		true
Contract liabilities increase due to annual renewals		$ 2,900
Minimum
Contract balances
The amount of time contract assets are transferred to receivables		3 years
Maximum
Contract balances
The amount of time contract assets are transferred to receivables		5 years
Dealflo Limited
Contract balances
Deferred revenue		$ 1,700

No definition available.

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Amount, before allowance for credit loss, of right to consideration in exchange for good or service transferred to customer, when right is conditioned on something other than passage of time.

+ References

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- Definition

Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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Amount of revenue recognized that was previously included in balance of obligation to transfer good or service to customer for which consideration from customer has been received or is due.

+ References

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Indicates (true/false) whether practical expedient is elected not to adjust consideration for effect of financing component when transfer and customer payment of good or service occurs within one year or less.

+ References

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The amount of time the contract assets are transferred to receivables when the right to billion normally occurs.

+ References

No definition available.

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Amount of increase in obligation to transfer good or service to customer for which consideration from customer has been received or is due from annual renewals.

+ References

No definition available.

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No definition available.

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