Stock Option Plans (Details 1) (Board Of Directors Plan [Member], USD $)	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012	Dec. 31, 2011
Board Of Directors Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares, Outstanding	145,250		55,250	100,250
Shares, Granted	45,000		90,000	0
Shares, Exercised	0		0	0
Shares, Forfeited	0		0	45,000
Shares, Outstanding	190,250		145,250	55,250
Shares, Options exercisable	100,250		55,250	55,250
Weighted-average fair value of options granted during the year	$ 1.17		$ 0.78	$ 0
Average Exercisable Price Outstanding (in dollars per share)	$ 3.30		$ 5.98	$ 9.42
Average Exercisable Price Granted (in dollars per share)	$ 2.37		$ 1.65	$ 0
Average Exercisable Price Exercised (in dollars per share)	$ 0		$ 0	$ 0
Average Exercisable Price Forfeited (in dollars per share)	$ 0		$ 0	$ 13.65
Average Exercisable Price Outstanding (in dollars per share)	$ 3.07		$ 3.30	$ 5.98
Average Exercisable Price, Options exercisable (in dollars per share)	$ 4.03		$ 5.98	$ 5.98
Aggregate Intrinsic Value Outstanding	$ 64,800	[1]
Aggregate Intrinsic Value Options exercisable at year end	$ 32,400	[1]

[1] The aggregate intrinsic value of a stock option in the table above represents the total pre-tax intrinsic value (the amount by which the current market value of the underlying stock exceeds the exercise price of the option) that would have been received by the option holders had all option holders exercised their options on December 31, 2013. This amount changes based on changes in the market value of Cornerstone's stock.