Goodwill and Other Intangible Assets - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Goodwill and Intangible Assets Disclosure [Line Items]
Amortization expense, related to finite-lived intangible assets	$ 2,626	$ 1,828	$ 876
Expected amortization expense, 2014	2,160
Expected amortization expense, 2015	2,045
Expected amortization expense, 2016	2,013
Expected amortization expense, 2017	1,799
Expected amortization expense, 2018	1,432
Noncontrolling interests	5,882	8,620
Goodwill	345,499	352,737	343,666
Estimated tax-deductible goodwill	10,444	12,745
Restatement Adjustment
Goodwill and Intangible Assets Disclosure [Line Items]
Noncontrolling interests	5,676
Goodwill	5,676
Nonredeemable noncontrolling interests	$ 4,106