Equity Investments - Schedule of Net Investment Activity (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Jun. 30, 2013	Jun. 30, 2012
Schedule Of Results Related To Equity Accounted Investees [Line Items]
Net foreign exchange rate impact	$ (35)	$ (1,168)
Tres Amigas [Member]
Schedule Of Results Related To Equity Accounted Investees [Line Items]
Beginning balance	2,853
Minority interest in net losses	(248)
Ending balance	2,605
Blade Dynamics Ltd. [Member]
Schedule Of Results Related To Equity Accounted Investees [Line Items]
Beginning balance	4,611
Minority interest in net losses
Net foreign exchange rate impact	(69)
Ending balance	$ 4,680

Amount after tax and reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 10A

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=28358780&loc=SL7669646-108580

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 830

-SubTopic 30

-Section 45

-Paragraph 20

-Subparagraph (b,c)

-URI http://asc.fasb.org/extlink&oid=6915805&loc=d3e32211-110900

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration