Contract Assets (Tables)

12 Months Ended

Dec. 31, 2018

Contract With Customer Asset And Liability [Abstract]

Changes In Contract Assets

Significant changes in the contract asset balance during the period are as follows:

	December 31,
(in thousands)		2018		2017
Beginning balance as of December 31, 2017	$	146,496	$	156,206
Revenue recognized		2,387,333		2,291,046
Amounts collected or invoiced		(2,393,747)		(2,300,756)
Ending balance as of December 31, 2018	$	140,082	$	146,496