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Long-Term Debt (Narrative) (Details) - USD ($) | 3 Months Ended | 9 Months Ended |  |
--- | --- | --- | --- | ---
Mar. 31, 2013 | Sep. 30, 2015 | Dec. 31, 2014 | Jan. 31, 2013
Debt Instrument [Line Items] |  |  |  |
Less unamortized debt issuance costs |  | $ 2,986,000 | $ 3,689,000 |
Senior Credit Agreement |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Maximum borrowing capacity under the revolving credit facility |  | 200,000,000 |  |
Revolving credit facility, increase, additional borrowings |  | 250,000,000 |  |
Standby letters of credit |  | $ 19,991,000 |  |
Fixed charge coverage ratio |  | 125.00% |  |
Senior Subordinated 8% Notes, Due December 1, 2015 |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Debt instrument, issued value | $ 204,000,000 |  |  |
Senior Subordinated Notes, interest rate | 8.00% |  |  |
Loss on extinguishment of debt | $ 7,166,000 |  |  |
Prepayment premium for extinguishment of debt | 3,702,000 |  |  |
Write-off deferred financing fees | 2,199,000 |  |  |
Write off of debt discount | $ 1,265,000 |  |  |
Revolving credit facility |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Revolving credit facility, annual commitment fee |  | 0.375% |  |
Revolving credit facility, availability amount |  | $ 88,164,000 |  |
Senior Subordinated 6.25% Notes |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Debt instrument, issued value |  |  |  | $ 210,000,000
Senior Subordinated Notes, interest rate | 6.25% | 6.25% |  |
Less unamortized debt issuance costs | $ 3,755,000 |  |  |
London Interbank Offering Rate (LIBOR) | Minimum | Revolving credit facility |  |  |  |
Debt Instrument [Line Items] |  |  |  |
LIBOR floor, plus |  | 2.00% |  |
London Interbank Offering Rate (LIBOR) | Maximum | Revolving credit facility |  |  |  |
Debt Instrument [Line Items] |  |  |  |
LIBOR floor, plus |  | 2.50% |  |

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