Shareholders' Equity (Tables)

6 Months Ended

Jun. 30, 2015

Equity [Abstract]

Summary of Activities in Common Stock

The following table details activity in our common stock:

	Six months ended June 30,
	2015						2014
	Shares			Amount			Shares			Amount
Purchase of common stock		(5	)	$	(645	)		(294	)	$	(22,815	)
Stock option exercises		355			6,729			265			4,117
Employee stock plan purchases		23			2,243			26			2,014
Shares issued for acquisition		13			1,519			—			—