CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Cash flows from operating activities:
Net income	$ 17,364	$ 12,680
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	3,689	3,617
Bad debt expense	368	161
Deferred taxes	97	268
Stock-based compensation expense	3,208	2,576
Excess tax benefits on stock-based compensation plans	(995)	(1,529)
Other	294	586
(Increase)/ decrease in operating assets:
Accounts receivable	4,908	1,664
Unbilled revenues	(15,611)	(18,597)
Prepaid expenses and other assets	939	(103)
Increase/ (decrease) in operating liabilities:
Accounts payable	8,563	3,009
Accrued expenses and other liabilities	(7,908)	(12,094)
Deferred revenues	265	(1,923)
Due to employees	4,711	3,191
Taxes payable	(3,704)	(5,244)
Net cash provided by/ (used in) operating activities	16,188	(11,738)
Cash flows used in investing activities:
Purchases of property and equipment	(2,157)	(2,887)
Payment for construction of corporate facilities	(1,488)	(808)
Employee housing loans	(294)	(2,834)
Proceeds from repayments of employee housing loans	419	0
(Increase)/decrease in restricted cash and time deposits, net (Note 3)	(5,387)	177
Decrease/(increase) in other long-term assets, net	(350)	(122)
Acquisition of businesses, net of cash acquired (Note 2)	(2,419)	0
Net cash used in investing activities	(11,676)	(6,474)
Cash flows from financing activities:
Proceeds related to stock options exercises	2,139	2,510
Excess tax benefits on stock-based compensation plans	995	1,529
Net cash provided by financing activities	3,134	4,039
Effect of exchange rate changes on cash and cash equivalents	(2,787)	(1,133)
Net increase/ (decrease) in cash and cash equivalents	4,859	(15,306)
Cash and cash equivalents, beginning of period	169,207	118,112
Cash and cash equivalents, end of period	$ 174,066	$ 102,806