Commitments and Contingencies (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011
Summary of minimum rental commitments under operating and capital leases
Remainder of 2012, Operating Lease	$ 1,805
2013, Operating Lease	1,790
2014, Operating Lease	1,756
2015, Operating Lease	2,014
2016, Operating Lease	2,027
2017 and thereafter, Operating Lease	10,159
Minimum lease payments, Operating Lease	19,551
Less amount representing interest, Operating Lease
Net Minimum Payments, Operating Lease	19,551
Remainder of 2012, Capital Lease	336
2013, Capital Lease	322
2014, Capital Lease	42
2015, Capital Lease
2016, Capital Lease
2017 and thereafter, Capital Lease
Minimum lease payments, Capital Lease	700
Less amount representing interest	52
Net Minimum Payments, Capital Lease	$ 648

Capital leases future minimum payments due in five years and thereafter.

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Operating leases future minimum payments interest included in payments.

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Operating leases future minimum payments net minimum payments.

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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 one year of the balance sheet date.

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

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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 third 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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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 total contractually required rental payments on capitalized leases net of deductions for: (i) executory costs, including any profit thereon, included in the minimum lease payments and (ii) the amount of imputed interest necessary to reduce the net minimum lease payments to present value.

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The total of future contractually required payments on leases defined as operating.

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For leases having an initial or remaining non-cancelable letter-terms in excess of one year, required rental payments due within one year of the balance sheet date relating to leases defined as operating.

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