Condensed Consolidated Statements of Operations Parenthetical (USD $)	12 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Mar. 31, 2010
Depreciation:
Net of (gains) losses on sale of real and personal property	$ (20,888,000)	$ (23,058,000)	$ (1,960,000)
Related party:
Related party revenues, net of eliminations	48,100,000	46,700,000	45,900,000
Related party, costs and expenses, net of eliminations	$ 44,100,000	$ 39,700,000	$ 37,200,000