FAIR VALUE MEASUREMENTS Schedule of Financial Assets and Liabilities (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
ASSETS:
Cash and cash equivalents	$ 102,076	$ 99,930
Marketable securities	116,718	54,161
Derivative financial instruments	368	71
Total assets	219,162	154,162
LIABILITIES:
Contingent consideration	(4,291)	(5,087)
Contingent contractual non-compliance liability	(49)	(246)
Derivative financial instruments	(139)	(249)
Total liabilities	(4,479)	(5,582)
U.S. government and municipal obligations
ASSETS:
Marketable securities	91,757	31,645
Commercial paper
ASSETS:
Marketable securities	14,581	12,390
Corporate bonds
ASSETS:
Marketable securities	10,380	5,166
Certificates of deposit
ASSETS:
Marketable securities	0	4,960
Level 1
ASSETS:
Cash and cash equivalents	82,079	99,930
Derivative financial instruments	0	0
Total assets	114,451	124,384
LIABILITIES:
Contingent consideration	0	0
Contingent contractual non-compliance liability	0	0
Derivative financial instruments	0	0
Total liabilities	0	0
Level 1 | U.S. government and municipal obligations
ASSETS:
Marketable securities	21,992	19,288
Level 1 | Commercial paper
ASSETS:
Marketable securities	0	0
Level 1 | Corporate bonds
ASSETS:
Marketable securities	10,380	5,166
Level 1 | Certificates of deposit
ASSETS:
Marketable securities	0	0
Level 2
ASSETS:
Cash and cash equivalents	19,997	0
Derivative financial instruments	368	71
Total assets	104,711	29,778
LIABILITIES:
Contingent consideration	0	0
Contingent contractual non-compliance liability	0	0
Derivative financial instruments	(139)	(249)
Total liabilities	(139)	(249)
Level 2 | U.S. government and municipal obligations
ASSETS:
Marketable securities	69,765	12,357
Level 2 | Commercial paper
ASSETS:
Marketable securities	14,581	12,390
Level 2 | Corporate bonds
ASSETS:
Marketable securities	0	0
Level 2 | Certificates of deposit
ASSETS:
Marketable securities	0	4,960
Level 3
ASSETS:
Cash and cash equivalents	0	0
Derivative financial instruments	0	0
Total assets	0	0
LIABILITIES:
Contingent consideration	(4,291)	(5,087)
Contingent contractual non-compliance liability	(49)	(246)
Derivative financial instruments	0	0
Total liabilities	(4,340)	(5,333)
Level 3 | U.S. government and municipal obligations
ASSETS:
Marketable securities	0	0
Level 3 | Commercial paper
ASSETS:
Marketable securities	0	0
Level 3 | Corporate bonds
ASSETS:
Marketable securities	0	0
Level 3 | Certificates of deposit
ASSETS:
Marketable securities	$ 0	$ 0