Equity (Earnings Per Share) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 28, 2013	Sep. 29, 2012	Sep. 28, 2013	Sep. 29, 2012
Numerator:
Income from continuing operations for purposes of calculating earnings per share	$ 30,980	$ 22,154	$ 84,912	$ 78,942
Income (loss) from discontinued operations	$ (113)	$ (182)	$ (1,183)	$ (63)
Denominator:
Weighted average shares outstanding-Basic (in shares)	47,910,649	47,625,806	47,950,018	48,028,602
Effect of dilutive securities:
2.25% senior convertible debentures (in shares)	0	0	0	0
Stock options and contingently issued restricted stock (in shares)	530,516	482,808	704,118	447,544
Weighted Average Number of Shares Outstanding, Diluted	48,441,165	48,108,614	48,654,136	48,476,146
Basic earnings per share from continuing operations attributable to common shareowners (in dollars per share)	$ 0.65	$ 0.47	$ 1.77	$ 1.64
Basic earnings (loss) per share from discontinued operations attributable to common shareowners (in dollars per share)	$ 0.00	$ 0.00	$ (0.02)	$ 0.00
Diluted earnings per share from continuing operations attributable to common shareowners (in dollars per share)	$ 0.64	$ 0.46	$ 1.75	$ 1.63
Diluted earnings (loss) per share from discontinued operations attributable to common shareowners (in dollars per share)	$ 0.00	$ 0.00	$ (0.02)	$ 0.00
Interest rate on debt (as a percent)	2.25%		2.25%
2.25% Senior convertible debentures
Effect of dilutive securities:
Interest rate on debt (as a percent)	2.25%		2.25%
Stock options [Member]
Antidilutive securities excluded from computation of earnings per share amount
Antidilutive securities excluded from computation of earnings per share amount (in shares)	2,652,660	4,667,739	2,363,878	4,590,418
Restricted Stock [Member]
Antidilutive securities excluded from computation of earnings per share amount
Antidilutive securities excluded from computation of earnings per share amount (in shares)	1,107,313	941,873