Capital Stock Repurchase Plan Transactions (Narrative) (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		6 Months Ended
	Jul. 31, 2016	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Mar. 31, 2016
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, amount authorized						$ 100,000
Stock Repurchase Program, Remaining Authorized Repurchase Amount		$ 50,200		$ 50,200
Purchases of treasury stock		$ 49,853	$ 29,762	$ 102,313	$ 29,762
Subsequent Event [Member]
Equity, Class of Treasury Stock [Line Items]
Purchases of treasury stock	$ 8,000