Common Stock (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Treasury shares issued (in shares)			1,032,493
Common stock repurchases, value	$ 52,103	$ 8,389	$ 68,608
Common Stock [Member]
Employee stock plans (in shares)	841,164	923,852	1,104,099
Treasury Stock [Member]
Common stock repurchases (in shares)	1,352,596	220,794	2,350,697
Common stock repurchases, value	$ 52,103	$ 8,389	$ 68,608
Männer Business [Member] | Common Stock [Member]
Treasury shares issued (in shares)	0	0	1,032,493