Segment Information (Net Revenues By Geographic Area) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Oct. 02, 2016	Jul. 03, 2016	Apr. 03, 2016	Dec. 31, 2015	Oct. 04, 2015	Jul. 05, 2015	Apr. 05, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Total net revenues	$ 158,236	$ 134,833	$ 146,392	$ 150,798	$ 164,243	$ 159,258	$ 166,906	$ 165,860	$ 590,259	$ 656,267	$ 841,446
United States [Member]
Segment Reporting Information [Line Items]
Total net revenues									232,650	284,227	406,153
SAUDI ARABIA
Segment Reporting Information [Line Items]
Total net revenues									68,693	33,155	7,980
United Kingdom [Member]
Segment Reporting Information [Line Items]
Total net revenues									27,579	36,005	58,479
France [Member]
Segment Reporting Information [Line Items]
Total net revenues									42,908	34,839	40,755
Europe [Member]
Segment Reporting Information [Line Items]
Total net revenues									32,460	24,508	40,290
GERMANY
Segment Reporting Information [Line Items]
Total net revenues									26,451	26,889	30,672
NORWAY
Segment Reporting Information [Line Items]
Total net revenues									21,668	43,502	50,634
CHINA
Segment Reporting Information [Line Items]
Total net revenues									11,157	13,255	15,397
CANADA
Segment Reporting Information [Line Items]
Total net revenues									32,750	46,575	41,054
Asia Pacific [Member]
Segment Reporting Information [Line Items]
Total net revenues									39,808	36,247	73,163
Other Countries [Member]
Segment Reporting Information [Line Items]
Total net revenues									$ 54,135	$ 77,065	$ 76,869