Debt (Schedule of Debt) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 27, 2014	Dec. 31, 2013
Schedule of Debt [Abstract]
Convertible Debt	$ 192,253	$ 192,238	$ 0
Revolving credit facility - unsecured	107,000		167,000
Bank term loans - unsecured	250,000		370,000
Long-term Debt	79,780		80,080
Debt, Long-term and Short-term, Combined Amount	$ 629,033		$ 617,080