Acquisition, Goodwill Impairment and Long-lived Asset Impairment (Details 2) (Nanda [Member], USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Jan. 01, 2011
Nanda [Member]
Business Acquisition, Pro Forma Information [Line Items]
Total revenues	$ 232,418	$ 188,685
Net income	$ 24,939	$ 45,544
Net income per share:
Basic	$ 1.10	$ 2.08
Diluted	$ 1.06	$ 1.98