Fair Value Measurements (Details) (Fair Value, Measurements, Recurring [Member], USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Mar. 31, 2011
ASSETS
Cash and cash equivalents	$ 134,444	$ 116,617
Restricted cash	1,962	3,787
Marketable securities (2)	4,987	1,120
Total	141,393	121,524
LIABILITIES
Contingent consideration related to acquisitions	6,556	13,658
Total	6,556	13,658
Quoted Prices in Active Markets for Identical Assets (Level 1)
ASSETS
Cash and cash equivalents	134,444	116,617
Restricted cash	1,962	3,787
Marketable securities (2)	4,987	1,120
Total	141,393	121,524
LIABILITIES
Contingent consideration related to acquisitions	0	0
Total	0	0
Significant Other Observable Inputs (Level 2)
ASSETS
Cash and cash equivalents	0	0
Restricted cash	0	0
Marketable securities (2)	0	0
Total	0	0
LIABILITIES
Contingent consideration related to acquisitions	0	12,743
Total	0	12,743
Unobservable Inputs (Level 3)
ASSETS
Cash and cash equivalents	0	0
Restricted cash	0	0
Marketable securities (2)	0	0
Total	0	0
LIABILITIES
Contingent consideration related to acquisitions	6,556	915
Total	$ 6,556	$ 915