Fair Value Measurements (Details) (Fair Value, Measurements, Recurring [Member], USD $) In Thousands, unless otherwise specified	Jun. 30, 2013		Mar. 31, 2013
ASSETS
Cash and cash equivalents	$ 118,212	[1]	$ 105,999	[1]
Restricted cash	3,647		5,488
Marketable securities	11,814	[2]	12,012	[2]
Total	133,673		123,499
LIABILITIES
Contingent consideration related to acquisitions	5,320		5,336
Total	5,320		5,336
Quoted Prices in Active Markets for Identical Assets (Level 1)
ASSETS
Cash and cash equivalents	118,212	[1]	105,999	[1]
Restricted cash	3,647		5,488
Marketable securities	11,814	[2]	12,012	[2]
Total	133,673		123,499
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	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	0	[2]	0	[2]
Total	0		0
LIABILITIES
Contingent consideration related to acquisitions	5,320		5,336
Total	$ 5,320		$ 5,336

[1] Cash equivalents consists of money market funds.

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