Preferred Common and Treasury Stock (Details) shares in Thousands	12 Months Ended
	Dec. 31, 2015 item shares	Dec. 31, 2014 shares
Preferred Common and Treasury Stock
Preferred stock, shares authorized	5,000	5,000
Number of series of preferred stock, minimum | item	1
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Description of voting rights for holders of common stock	one vote per share