Earnings Per Share: (Details)	3 Months Ended		6 Months Ended
	Jun. 28, 2014	Jun. 29, 2013	Jun. 28, 2014	Jun. 29, 2013
Earnings Per Share:
Denominator for basic EPS - weighted average common shares	5,109,049	5,024,284	5,128,789	5,010,803
Dilutive shares associated with option plans	134,074	176,308	146,750	190,841
Denominator for diluted EPS - weighted average common shares and dilutive potential common shares	5,243,123	5,200,592	5,275,539	5,201,644
Options excluded from EPS calculation - anti-dilutive (in shares)	31,813	17,474	23,002	18,451