Credit Facility and Long-Term Debt (Interest Expense) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Debt Disclosure [Abstract]
Contractual coupon interest	$ 40,155	$ 14,043	$ 5,682
Amortization of debt issuance costs	1,822us-gaap_AmortizationOfFinancingCosts	1,114us-gaap_AmortizationOfFinancingCosts	648us-gaap_AmortizationOfFinancingCosts
Amortization of Debt Discount, Net	1,293	343	102
Total Interest Expense related to senior notes	$ 43,270us-gaap_InterestExpenseDebt	$ 15,500us-gaap_InterestExpenseDebt	$ 6,432us-gaap_InterestExpenseDebt

Amount of noncash expense included in interest expense to amortize debt discount and premium associated with the related debt instruments. Excludes amortization of financing costs. Alternate captions include noncash interest expense.

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Amount of noncash expense included in interest expense to issue debt and obtain financing associated with the related debt instruments. Alternate captions include noncash interest expense.

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Amount of the cost of borrowed funds accounted for as interest expense for debt.

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Represents the portion of interest incurred in the period on debt arrangements that was charged against earnings, excluding amortization of debt discount (premium) and financing costs.

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