Related Party Revenue (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Related party transactions:
Interest income revenue	$ 3,339	$ 6,224	$ 7,160	$ 12,393
Management fees revenue	4,902	4,826	9,762	9,561
Revenue from related parties	8,241	11,050	16,922	21,954
SAC Holdings
Related party transactions:
Interest income revenue	1,981	4,858	4,457	9,674
Management fees revenue	3,857	3,821	7,686	7,550
Private Mini
Related party transactions:
Interest income revenue	1,358	1,366	2,703	2,719
Management fees revenue	573	554	1,140	1,106
Mercury
Related party transactions:
Management fees revenue	$ 472	$ 451	$ 936	$ 905