Shareholders' Equity (Tables)

6 Months Ended

Jun. 30, 2016

Equity [Abstract]

Summary of Activities in Common Stock

The following table details activity in our common stock:

	Six months ended June 30,
	2016						2015
	Shares			Amount			Shares			Amount
Purchases of common stock		(758	)	$	(94,497	)		(5	)		(645	)
Stock option exercises		241			5,793			355		$	6,729
Employee stock plan purchases		23			2,818			23			2,243
Shares issued for acquisition		—			—			13			1,519