Stockholders' Equity - Schedule of Stock Repurchases (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Stockholders Equity [Line Items]
Total cost	$ 21,883	$ 14,220
2016 Stock Repurchase Program
Stockholders Equity [Line Items]
Shares of common stock repurchased and retired	328	337
Average price paid per share	$ 66.70	$ 42.17
Total cost	$ 21,877	$ 14,213

Equity impact of the value of stock that has been repurchased and retired during the period. The excess of the purchase price over par value can be charged against retained earnings (once the excess is fully allocated to additional paid in capital).

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