Stock Transactions Stock Transactions (Share Repurchases) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Sep. 30, 2015
Equity [Abstract]
Treasury Stock, Shares, Acquired	782,437	252,642	2,538,718	3,573,797
Treasury Stock, Value, Acquired, Cost Method	$ 70,702	$ 23,480	$ 230,124	$ 324,306
Treasury Stock Acquired, Average Cost Per Share	$ 90.36	$ 92.94	$ 90.65	$ 90.75