Revenue Recognition (Tables)

9 Months Ended

Sep. 30, 2018

Revenues [Abstract]

Contract with Customer, Asset and Liability

A summary of significant net changes in the contract assets and the contract liabilities balances during the period is as follows:

	2018
	Contract liabilities, less contract assets
	(in thousands)
Beginning balance, January 1	$	59,808
Changes due to business combination	36,936
Revenues recognized from beginning contract liability	(31,688		)
Increases due to amounts collected or due	200,428
Revenues recognized from current period increases	(142,439		)
Other	(847		)
Ending balance, September 30	$	122,198