Financing Arrangments-Interest (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 29, 2013	Sep. 30, 2012	Sep. 29, 2013	Sep. 30, 2012
1% Sr. Convertible Notes due 2013 [Member]
Interest Cost Recognized For Convertible Notes
Contractual interest coupon	$ 0	$ 2,319	$ 3,481	$ 6,959
Amortization of bond issuance costs	0	695	1,014	2,087
Amortization of bond discount	0	13,515	21,022	39,816
Total interest cost recognized	0	16,529	25,517	48,862
1.5% Sr. Convertible Notes due 2017 [Member]
Interest Cost Recognized For Convertible Notes
Contractual interest coupon	3,750	3,750	11,250	11,250
Amortization of bond issuance costs	667	667	2,000	2,000
Amortization of bond discount	9,859	9,170	29,180	27,111
Total interest cost recognized	$ 14,276	$ 13,587	$ 42,430	$ 40,361