Equity Method Investments (Details) (USD $) In Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Equity Method Investment Summarized Financial Information
Revenues	$ 91,832	$ 60,597	$ 243,688	$ 174,517
Gross profit	21,356	17,561	68,966	57,819
Income before provision for income taxes	14,772	12,494	47,607	42,237
Provision for income taxes	(4,189)	(3,570)	(14,237)	(11,524)
Net income	$ 10,583	$ 8,924	$ 33,370	$ 30,713