CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Cash flows from operating activities:
Net income	$ 32,178	$ 26,798
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	9,140	7,471
Bad debt expense	769	803
Deferred taxes	195	530
Stock-based compensation expense	9,099	6,426
Excess tax benefit on stock-based compensation plans	(2,161)	(3,250)
Other	2,336	1,139
(Increase)/ decrease in operating assets:
Accounts receivable	(7,172)	(6,563)
Unbilled revenues	(24,254)	(24,695)
Prepaid expenses and other assets	1,000	981
Increase/ (decrease) in operating liabilities:
Accounts payable	5,899	2,630
Accrued expenses and other liabilities	(2,172)	(12,695)
Deferred revenues	(255)	(3,059)
Due to employees	6,627	1,881
Taxes payable	1,798	(2,177)
Net cash provided by/ (used in) operating activities	33,027	(3,780)
Cash flows used in investing activities:
Purchases of property and equipment	(4,445)	(8,998)
Payment for construction of corporate facilities	(2,282)	(1,006)
Employee housing loans	(799)	(5,172)
Proceeds from repayments of employee housing loans	856	821
Decrease in restricted cash and time deposits, net	303	709
Increase in other long-term assets, net	(346)	(320)
Acquisition of businesses, net of cash acquired (Note 2)	(26,498)	(20)
Net cash used in investing activities	(33,211)	(13,986)
Cash flows from financing activities:
Proceeds related to stock options exercises	5,413	5,353
Excess tax benefit on stock-based compensation plans	2,161	3,250
Net cash provided by financing activities	7,574	8,603
Effect of exchange rate changes on cash and cash equivalents	(1,522)	(1,474)
Net increase/ (decrease) in cash and cash equivalents	5,868	(10,637)
Cash and cash equivalents, beginning of period	169,207	118,112
Cash and cash equivalents, end of period	175,075	107,475
Noncash financing activities:
Deferred consideration payable	5,418	0
Contingent consideration payable	$ 28,293	$ 0