Summary of Significant Accounting Policies Accumulated Other Comprehensive Income (Loss), Net of Tax (Details) - USD ($)	3 Months Ended	12 Months Ended
Dec. 31, 2016	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014	Dec. 28, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, before Tax	$ 0	$ 33,683	$ 33,683	$ 0	$ 0
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance		771,774	3,126,239	3,441,997
Change during the year		799,197	(2,354,465)		(315,758)
Ending balance	1,570,971	1,570,971	771,774	3,126,239	3,441,997
Cumulative Translation Adjustment
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance		532,342	1,534,075	2,524,701
Change during the year		814,017	(1,001,733)		(990,626)
Ending balance	1,346,359	1,346,359	532,342	1,534,075	2,524,701
Unrealized Holding Gain (Loss) on Marketable Securities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance		205,749	1,592,164	917,296
Change during the year		(14,820)	(1,386,415)		674,868
Ending balance	$ 190,929	$ 190,929	$ 205,749	$ 1,592,164	$ 917,296