Note 16. Earnings Per Share - Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2013
Dividends Declared, Basic									$ 7,705	$ 7,527	$ 7,450
Undistributed Earnings, Basic									12,595	25,934	12,429
Net Income (Loss), Basic									$ 20,300	$ 33,461	$ 19,879
Average Number of Shares Outstanding, Basic									38,645	38,404	38,063
Dividends Declared and Assumed Dividends on Diluted Shares									$ 7,770	$ 7,641	$ 7,450
Undistributed Earnings, Diluted									12,530	25,820	12,429
Net Income (Loss), Diluted									$ 20,300	$ 33,461	$ 19,879
Average Number of Shares Outstanding, Diluted									38,971	39,037	38,063
Class A Common Stock
Dividends Declared, Basic									$ 536	$ 1,437	$ 1,495
Undistributed Earnings, Basic									1,053	5,420	2,803
Net Income (Loss), Basic									$ 1,589	$ 6,857	$ 4,298
Average Number of Shares Outstanding, Basic									3,231	8,026	8,584
Basic Earnings Per Share:	$ 0.11	$ 0.12	$ 0.05	$ 0.20	$ 0.20	$ 0.18	$ 0.24	$ 0.24	$ 0.49	$ 0.85	$ 0.50
Dividends Declared and Assumed Dividends on Diluted Shares									$ 536	$ 1,550	$ 1,495
Undistributed Earnings, Diluted									1,039	5,723	2,803
Net Income (Loss), Diluted									$ 1,575	$ 7,273	$ 4,298
Average Number of Shares Outstanding, Diluted									3,231	8,652	8,584
Diluted Earnings Per Share:	0.11	0.12	0.05	0.20	0.20	0.18	0.23	0.23	$ 0.49	$ 0.84	$ 0.50
Class B Common Stock
Dividends Declared, Basic									$ 7,169	$ 6,090	$ 5,955
Undistributed Earnings, Basic									11,542	20,514	9,626
Net Income (Loss), Basic									$ 18,711	$ 26,604	$ 15,581
Average Number of Shares Outstanding, Basic									35,414	30,378	29,479
Basic Earnings Per Share:	0.12	0.13	0.07	0.21	0.21	0.19	0.24	0.24	$ 0.53	$ 0.88	$ 0.53
Dividends Declared and Assumed Dividends on Diluted Shares									$ 7,234	$ 6,091	$ 5,955
Undistributed Earnings, Diluted									11,491	20,097	9,626
Net Income (Loss), Diluted									$ 18,725	$ 26,188	$ 15,581
Average Number of Shares Outstanding, Diluted									35,740	30,385	29,479
Diluted Earnings Per Share:	$ 0.12	$ 0.13	$ 0.07	$ 0.21	$ 0.20	$ 0.19	$ 0.24	$ 0.24	$ 0.52	$ 0.86	$ 0.53