CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - UNAUDITED (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
OPERATING ACTIVITIES:
Net cash used in operating activities	$ (19,685)	$ (22,881)
INVESTING ACTIVITIES:
Purchases of investments	(6,873)	(5,925)
Proceeds from sale of investments	7,357	35,396
Proceeds from maturity of investments	4,306	1,044
Purchases of property and equipment	(14,371)	(8,462)
Other investing activities, net	10	684
Net cash provided by (used in) investing activities	(9,571)	22,737
FINANCING ACTIVITIES:
Repayment of debt	(1,807)	(4,860)
Repurchase of shares and payment of withholding taxes on RSU exercise	(1,019)
Proceeds from debt	17,413
Net cash provided by (used in) financing activities	14,587	(4,860)
Effect of exchange rate changes on cash	(480)	(312)
DECREASE IN CASH AND CASH EQUIVALENTS	(15,149)	(5,316)
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	125,547	114,759
CASH AND CASH EQUIVALENTS, END OF PERIOD	110,398	109,443
SUPPLEMENTAL CASH FLOW INFORMATION:
Payment for federal, foreign and state income taxes	2,567
Interest paid, net of amounts capitalized	827	525
Non-cash investing and financing activities:
Unpaid liability incurred for construction costs	7,102
Mortgage incurred to purchase real estate	$ 360	$ 6,087