Acquisition (Details) (USD $)	9 Months Ended
	Dec. 31, 2011
Acquisition [Abstract]
Acquisition cost dynaTrace	$ 255,800,000
Direct acquisition costs recognized as administrative and general expense	300,000
Goodwill recognized on acquisition	210,900,000
Amount borrowed under the amended credit facility	129,500,000
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated fair value of intangible assets subject to amortization	42,000,000
Developed Technology Rights [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated fair value of intangible assets subject to amortization	28,500,000
Useful life of amortizable intangible assets (in years)	5
Trade Names [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated fair value of intangible assets subject to amortization	9,800,000
Useful life of amortizable intangible assets (in years)	3
Customer Relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated fair value of intangible assets subject to amortization	$ 3,700,000
Useful life of amortizable intangible assets (in years)	10