Significant Accounting Policies (Narrative) (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Accounting Policies [Abstract]
Debt and Capital Lease Obligations	$ 125,322	$ 133,805
Long-term Debt, Fair Value	131,300	$ 139,100
Stock Repurchase Program, Authorized Amount	$ 200,000
Total Stock Repurchased And Retired Shares	2,515,519
Total Stock Repurchased And Retired Value	$ 164,300
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 35,700