Other Accrued Liabilities (Details) (USD $) In Thousands	Sep. 30, 2011	Dec. 31, 2010
Other accrued liabilities
Deferred revenue	$ 6,533	$ 8,617
Accrued health insurance	5,594	4,970
Deferred rent	3,918	3,456
Accrued consulting fees	2,760	2,760
Holdbacks and earnouts	2,536	2,447
Customer deposits	2,517	2,966
Accrued lab service rebates	212	2,535
Other	21,109	18,018
Other accrued liabilities	$ 45,179	$ 45,769