Note 10. Repurchases of common STOCK

We primarily acquire shares by repurchases in the open market. However, we also acquire shares that are surrendered by employees in payment for the minimum required statutory withholding taxes due on the vesting of restricted stock units and the settlement of deferred stock units, otherwise referred to herein as employee surrenders.

We issue shares of treasury stock upon the vesting of certain restricted stock units and upon the exercise of certain stock options. The number of shares of treasury stock issued during the three and nine months ended September 30, 2017 and 2016 was not material.

The following is a summary of our open market common stock repurchases, reported on a trade date basis, and shares acquired through employee surrender for the three and nine months ended September 30, 2017 and 2016 (in thousands, except per share amounts):


	For the Three Months Ended				For the Nine Months Ended
	September 30,				September 30,
	2017		2016		2017		2016

Shares repurchased in the open market		312		142		1,398		1,119
Shares acquired through employee surrender for statutory tax withholding		2		2		55		56
Total shares repurchased		314		144		1,453		1,175

Cost of shares repurchased in the open market	$	50,413	$	15,260	$	215,320	$	88,235
Cost of shares for employee surrenders		370		218		7,829		3,950
Total cost of shares	$	50,783	$	15,478	$	223,149	$	92,185

Average cost per share - open market repurchase	$	161.57	$	107.38	$	153.99	$	78.84
Average cost per share - employee surrenders	$	155.14	$	112.91	$	142.15	$	70.33
Average cost per share - total	$	161.52	$	107.46	$	153.54	$	78.43