Shareholders' Equity

3 Months Ended

Mar. 31, 2018

6. Shareholders’ Equity

Through March 31, 2018, we had announced authorizations by our Board of Directors of repurchases of shares of common stock, which in the aggregate authorized expenditures of up to $2.4 billion. On April 25, 2018, we announced that our Board of Directors authorized the expenditure of an additional $100,000 to repurchase shares of common stock. Under the remaining repurchase authorizations, shares may be purchased from time to time in open market transactions, subject to market conditions.

The following table summarizes common stock repurchases under authorized programs:



	Three months ended March 31,
	2018		2017
Shares of common stock repurchased		219		141
Total cost of common stock repurchased	$	68,038	$	57,959

As of March 31, 2018, $50,243 was available to repurchase shares under the announced repurchase authorizations. Shares repurchased are being held in treasury stock until such time as they are reissued or retired at the discretion of the Board of Directors.

During the three months ended March 31, 2018, 12 shares of common stock at a total cost of $3,988 were netted and surrendered as payment for minimum statutory withholding obligations in connection with the vesting of outstanding stock awards. Shares surrendered by the participants in accordance with the applicable award agreements and plan are deemed repurchased by us but are not part of publicly announced share repurchase programs.