Consolidated Statements of Shareholders' Equity (USD $) In Thousands	Total	Common Stock	Retained Earnings
Balance at May. 31, 2010	$ 229,962	$ 33,555	$ 196,407
Balance (in shares) at May. 31, 2010		23,961
Exercise of stock options and issuance of restricted shares (in shares)		20
Exercise of stock options and issuance of restricted shares	197	197
Excess tax benefit for share based compensation, net of tax deficit	34	34
Non-cash stock compensation expense	956	956
Dividends declared	(14,530)		(14,530)
Net income and total comprehensive income for the year ended May 31, 2011	23,756		23,756
Balance at May. 31, 2011	240,375	34,742	205,633
Balance (in shares) at May. 31, 2011		23,981
Exercise of stock options and issuance of restricted shares (in shares)		7
Excess tax benefit for share based compensation, net of tax deficit	46	46
Non-cash stock compensation expense	1,438	1,438
Dividends declared	(19,453)		(19,453)
Net settlement of shares	(47)	(47)
Net income and total comprehensive income for the year ended May 31, 2011	25,772		25,772
Balance at May. 31, 2012	248,131	36,179	211,952
Balance (in shares) at May. 31, 2012		23,988
Exercise of stock options and issuance of restricted shares (in shares)		8
Excess tax benefit for share based compensation, net of tax deficit	251	251
Non-cash stock compensation expense	1,330	1,330
Dividends declared	(43,881)		(43,881)
Net settlement of shares	(36)	(36)
Net income and total comprehensive income for the year ended May 31, 2011	22,754		22,754
Balance at May. 31, 2013	$ 228,549	$ 37,724	$ 190,825
Balance (in shares) at May. 31, 2013		23,996