Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 74,389	$ 79,839	$ 104,470	$ 104,925
Other comprehensive loss, net of tax:
Amortization of loss on cash flow hedge	216	216	431	431
Foreign currency translation adjustment	(452)	(1,869)	(659)	(1,014)
Other comprehensive loss, net of tax	(236)	(1,653)	(228)	(583)
Comprehensive income	$ 74,153	$ 78,186	$ 104,242	$ 104,342

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income. Excludes changes in equity resulting from investments by owners and distributions to owners.

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