FAIR VALUE MEASUREMENT OF ASSETS AND LIABILITIES (Details 2) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Mar. 31, 2014
Financial Instruments Measured at Fair Value on a Recurring Basis and Nonrecurring Basis
Transfers out of Level 1 and into Level 2 related to assets and liabilities measured on a recurring and nonrecurring basis	$ 0	$ 0
Transfers out of Level 2 and into Level 1 related to assets and liabilities measured on a recurring and nonrecurring basis	0	0
Transfers out of Level 1 and into Level 2 related to liabilities measured on a recurring and nonrecurring basis	0	0
Transfers out of Level 2 and into Level 1 related to liabilities measured on a recurring and nonrecurring basis	0	0
Recurring Basis | Level 1 | Deferred compensation plan assets: Mutual funds, money market accounts and equity securities
Financial Instruments Measured at Fair Value on a Recurring Basis and Nonrecurring Basis
Total Assets	8,981,000		9,456,000
Recurring Basis | Level 2 | Money market funds and time deposits
Financial Instruments Measured at Fair Value on a Recurring Basis and Nonrecurring Basis
Total Assets	561,002,000		552,928,000
Recurring Basis | Level 2 | Foreign exchange forward contracts (Note 7)
Financial Instruments Measured at Fair Value on a Recurring Basis and Nonrecurring Basis
Total Assets	19,556,000		8,186,000
Total Liabilities	(44,394,000)		(17,406,000)
Recurring Basis | Level 2 | Deferred compensation plan assets: Mutual funds, money market accounts and equity securities
Financial Instruments Measured at Fair Value on a Recurring Basis and Nonrecurring Basis
Total Assets	35,866,000		36,751,000
Recurring Basis | Level 3 | Deferred purchase price receivable (Note 9)
Financial Instruments Measured at Fair Value on a Recurring Basis and Nonrecurring Basis
Total Assets	674,642,000		470,908,000
Recurring Basis | Level 3 | Contingent consideration in connection with business acquisitions
Financial Instruments Measured at Fair Value on a Recurring Basis and Nonrecurring Basis
Total Liabilities	(8,402,000)		(11,300,000)
Recurring Basis | Total | Money market funds and time deposits
Financial Instruments Measured at Fair Value on a Recurring Basis and Nonrecurring Basis
Total Assets	561,002,000		552,928,000
Recurring Basis | Total | Deferred purchase price receivable (Note 9)
Financial Instruments Measured at Fair Value on a Recurring Basis and Nonrecurring Basis
Total Assets	674,642,000		470,908,000
Recurring Basis | Total | Foreign exchange forward contracts (Note 7)
Financial Instruments Measured at Fair Value on a Recurring Basis and Nonrecurring Basis
Total Assets	19,556,000		8,186,000
Total Liabilities	(44,394,000)		(17,406,000)
Recurring Basis | Total | Deferred compensation plan assets: Mutual funds, money market accounts and equity securities
Financial Instruments Measured at Fair Value on a Recurring Basis and Nonrecurring Basis
Total Assets	44,847,000		46,207,000
Recurring Basis | Total | Contingent consideration in connection with business acquisitions
Financial Instruments Measured at Fair Value on a Recurring Basis and Nonrecurring Basis
Total Liabilities	(8,402,000)		(11,300,000)
Nonrecurring Basis | Level 2
Assets held for sale
Assets held for sale	13,500,000		43,500,000
Carry value of assets held for sale of properties sold	$ 39,900,000