Leases (Details 1) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Future minimum payments for capital leases
2012	$ 5,028
2013	5,129
2014	5,191
2015	5,280
2016	4,034
Total minimum payments required	24,662
Less: amount representing interest	(7,648)
Present value of future minimum lease payments	17,014
Less: current portion	(2,432)
Non-current portion	$ 14,582	$ 17,014

Amount equal to the present value (the principal) at the beginning of the lease term of minimum lease payments during the lease term (excluding that portion of the payments representing executory costs such as insurance, maintenance, and taxes to be paid by the lessor, together with any profit thereon) net of payments or other amounts applied to the principal, through the balance sheet date and due to be paid within one year (or one operating cycle, if longer) of the balance sheet date.

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The total of contractually required rental payments on leases meeting the criteria for capitalization.

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Contractually required rental payments on leases meeting the criteria for capitalization, due within the fourth year from the balance sheet date.

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Contractually required rental payments on leases meeting the criteria for capitalization, due within the second year from the balance sheet date.

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Contractually required rental payments due on leases meeting the criteria for capitalization, after the fifth year from the balance sheet date.

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Amount necessary to reduce net minimum lease payments to present value calculated at the lesser of the interest rate implicit in the lease (if known) or the entity's incremental borrowing rate (as defined) at inception of the lease.

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The discounted value of future cash flows under leases meeting the criteria for capitalization.

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