Related Party Revenue (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Related party transactions:
Management fees revenue	$ 5,161	$ 4,860
Revenue from related parties	8,417	8,681
SAC Holdings
Related party transactions:
Interest income revenue	1,919	2,476
Management fees revenue	4,074	3,829
Private Mini
Related party transactions:
Interest income revenue	1,337	1,345
Management fees revenue	594	567
Mercury
Related party transactions:
Management fees revenue	$ 493	$ 464