Fair Value Measurements (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013		Mar. 31, 2012
ASSETS
Cash and cash equivalents	$ 105,999	[1]	$ 134,444	[1]
Restricted cash	5,488		1,962
Marketable securities (2)	12,012	[2]	4,987	[2]
Total	123,499		141,393
LIABILITIES
Contingent consideration related to acquisitions	5,336		6,556
Total	5,336		6,556
Quoted Prices in Active Markets for Identical Assets (Level 1)
ASSETS
Cash and cash equivalents	105,999	[1]	134,444	[1]
Restricted cash	5,488		1,962
Marketable securities (2)	12,012	[2]	4,987	[2]
Total	123,499		141,393
LIABILITIES
Contingent consideration related to acquisitions	0		0
Total	0		0
Significant Other Observable Inputs (Level 2)
ASSETS
Cash and cash equivalents	0	[1]	0	[1]
Restricted cash	0		0
Marketable securities (2)	0	[2]	0	[2]
Total	0		0
LIABILITIES
Contingent consideration related to acquisitions	0		0
Total	0		0
Unobservable Inputs (Level 3)
ASSETS
Cash and cash equivalents	0	[1]	0	[1]
Restricted cash	0		0
Marketable securities (2)	0	[2]	0	[2]
Total	0		0
LIABILITIES
Contingent consideration related to acquisitions	5,336		6,556
Total	$ 5,336		$ 6,556

[1] Cash and cash equivalents consists of money market funds.

[2] Marketable securities consists of fixed-income securities.