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Derivatives and Hedging Activities - Narrative (Details) - USD ($) |  | 12 Months Ended |
--- | --- | --- | ---
Sep. 06, 2017 | Dec. 31, 2017 | Dec. 31, 2016 | Sep. 22, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract] |  |  |  |
Payment to terminate existing interest rate swap contract | $ 1,100,000 |  |  |
Derivative liability, notional amount |  | $ 433,000,000 | $ 153,600,000 | $ 100,000,000
Derivative, fixed interest rate |  |  |  | 1.94%
Hedge ineffectiveness |  | $ 0 | $ 0 |

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- Definition Payments To Terminate Derivative Instrument + References No definition available. + Details
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- Definition Fixed interest rate related to the interest rate derivative. + References No definition available. + Details
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- Definition Nominal or face amount used to calculate payments on the derivative liability. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1B -URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5580258-113959 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1A -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5579245-113959 + Details
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- Definition Amount of gain (loss)recognized in the income statement from the hedging ineffectiveness of a fair value hedge. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 25 -Section 50 -Paragraph 1 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=6886632&loc=d3e76258-113986 + Details
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