CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Stock compensation expense	$ 5,414	$ 10,439	$ 15,021	$ 18,085
Changes in fair value of contingent consideration	(2,149)	70	(2,005)	303
Net of income tax (benefit) expense	$ 131	$ 42	$ 231	$ (59)

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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Amount of increase (decrease) in the value of a contingent consideration liability, including, but not limited to, differences arising upon settlement.

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Amount of tax expense (benefit) before reclassification adjustments of unrealized holding gain (loss) on available-for-sale securities.

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