Shareholders' Equity (Restricted Stock Awards) (Details) - USD ($)							9 Months Ended
	Aug. 31, 2016	May 31, 2016	Feb. 29, 2016	Aug. 31, 2015	May 29, 2015	Feb. 27, 2015	Sep. 30, 2016
Restricted Stock Awards Disclosure [Abstract]
Aggregate shares of restricted stock granted (in shares)	3,485	3,925	5,190	4,940	4,530	4,974
Issuance of restricted common stock for services	$ 97,000	$ 97,000	$ 97,000	$ 97,000	$ 97,000	$ 116,000	$ 290,000
Weighted average fair value per share (in dollars per share)	$ 27.79	$ 24.68	$ 18.65	$ 19.61	$ 21.38	$ 23.35