Notes Payable and Borrowings under Capital Leases - Components of Company's Notes Payable and Borrowings under Capital Leases Balances (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Debt And Capital Lease Obligations [Abstract]
Notes payable under credit facility	$ 544,875us-gaap_NotesPayable	$ 818,425us-gaap_NotesPayable
Capital leases	275us-gaap_CapitalLeaseObligations	452us-gaap_CapitalLeaseObligations
Less current portion	(20,738)	(6,669)
Notes payable and borrowings under capital leases, less current portion	$ 524,412	$ 812,208

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.

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Amount of long-term debt and capital lease obligation due after one year or beyond the normal operating cycle, if longer.

+ References

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Amount of long-term debt and capital leases due within one year or the normal operating cycle, if longer.

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- Definition

Including the current and noncurrent portions, aggregate carrying amount of all types of notes payable, as of the balance sheet date, with initial maturities beyond one year or beyond the normal operating cycle, if longer.

+ References

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