CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Cash flows from operating activities:
Net income	$ 74,503	$ 56,818
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	17,150	12,496
Bad debt expense	1,690	910
Deferred taxes	(11)	535
Stock-based compensation expense	37,520	33,350
Excess tax benefit on stock-based compensation plans	(4,769)	(3,118)
Other	1,834	2,358
(Increase)/decrease in operating assets:
Accounts receivable	(14,801)	(3,575)
Unbilled revenues	15,633	(49,110)
Prepaid expenses and other assets	(630)	29
Increase/(decrease) in operating liabilities:
Accounts payable	2,011	8,128
Accrued expenses and other liabilities	(26,942)	10,844
Deferred revenues	540	(607)
Due to employees	8,047	4,295
Taxes payable	(609)	(8,799)
Net cash provided by operating activities	111,166	64,554
Cash flows from investing activities:
Purchases of property and equipment	(19,981)	(9,533)
Payment for construction of corporate facilities	0	(4,671)
Employee housing loans issued	(1,361)	(1,993)
Proceeds from repayments of employee housing loans	1,597	1,611
Decrease/(increase) in restricted cash and time deposits, net	30,001	(29,947)
Increase in other long-term assets, net	(2,660)	(988)
Proceeds from foreign currency derivatives	104	0
Payments for foreign currency derivatives	(91)	0
Acquisition of businesses, net of cash acquired	(4,499)	(27,654)
Net cash provided by/(used in) investing activities	3,110	(73,175)
Cash flows from financing activities:
Proceeds from stock option exercises	15,850	17,607
Excess tax benefit on stock-based compensation plans	4,769	3,118
Proceeds from debt (Note 5)	20,000	15,000
Repayment of debt (Note 5)	(22,096)	0
Proceeds from government grants	135	0
Acquisition of business, deferred consideration	(2,260)	(30,274)
Net cash provided by/(used in) financing activities	16,398	5,451
Effect of exchange rate changes on cash and cash equivalents	504	(2,921)
Net increase/(decrease) in cash and cash equivalents	131,178	(6,091)
Cash and cash equivalents, beginning of period	199,449	220,534
Cash and cash equivalents, end of period	$ 330,627	$ 214,443