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Debt - Narrative (Details) - USD ($) |  | 3 Months Ended | 6 Months Ended
--- | --- | --- | ---
May 24, 2018 | Jun. 30, 2019 | Jun. 30, 2018 | Jun. 30, 2019 | Jun. 30, 2018
Debt Instrument [Line Items] |  |  |  |  |
Term loan |  | $ 148,500,000 |  | $ 148,500,000 |
Interest expense |  | 3,071,000 | $ 5,560,000 | $ 6,132,000 | $ 8,979,000
Secured Debt | 2018 Term Loan |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Debt instrument face amount | $ 150,000,000 |  |  |  |
Debt instrument term (years) | 5 years |  |  |  |
Interest rate during period (percent) |  |  |  | 6.95% |
Frequency of periodic payment |  |  |  | Quarterly |
Periodic payment of principal |  |  |  | $ 375,000 |
Interest expense |  | 2,800,000 |  | 5,700,000 |
Unamortized issuance costs |  | 2,200,000 |  | $ 2,200,000 |
Debt instrument covenant, maximum debt-to-total capitalization ratio |  |  |  | 35.00% |
Secured Debt | 2018 Term Loan | Eurodollar |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Variable rate floor (percent) |  |  |  | 1.00% |
Basis spread on variable rate (percent) |  |  |  | 4.75% |
Senior Secured Debt | 2015 Term Loan |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Debt instrument face amount | $ 150,000,000 |  |  |  |
Revolving Credit Facility | 2018 Revolving Credit Facility |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Debt instrument term (years) | 3 years |  |  |  |
Credit facility borrowing capacity | $ 85,000,000 |  |  |  |
Borrowings outstanding |  | 0 |  | $ 0 |
Commitment fee (percent) |  |  |  | 0.40% |
Commitment fees in interest expense |  | 100,000 |  | $ 200,000 |
Debt issuance costs | $ 1,500,000 |  |  |  |
Interest expense from amortization of debt issuance costs |  | 100,000 |  | 300,000 |
Remaining deferred issuance costs, net of accumulated amortization |  | $ 1,000,000.0 |  | $ 1,000,000.0 |
Debt instrument covenant, maximum debt-to-total capitalization ratio |  |  |  | 35.00% |
Revolving Credit Facility | 2018 Revolving Credit Facility | Minimum |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Commitment fee (percent) |  |  |  | 0.30% |
Revolving Credit Facility | 2018 Revolving Credit Facility | Maximum |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Commitment fee (percent) |  |  |  | 0.60% |
Revolving Credit Facility | 2018 Revolving Credit Facility | Base Rate |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Variable rate floor (percent) |  |  |  | 1.00% |
Revolving Credit Facility | 2018 Revolving Credit Facility | Base Rate | Minimum |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Basis spread on variable rate (percent) |  |  |  | 1.00% |
Revolving Credit Facility | 2018 Revolving Credit Facility | Base Rate | Maximum |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Basis spread on variable rate (percent) |  |  |  | 2.50% |
Revolving Credit Facility | 2018 Revolving Credit Facility | Eurodollar |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Variable rate floor (percent) |  |  |  | 0.00% |
Revolving Credit Facility | 2018 Revolving Credit Facility | Eurodollar | Minimum |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Basis spread on variable rate (percent) |  |  |  | 2.00% |
Revolving Credit Facility | 2018 Revolving Credit Facility | Eurodollar | Maximum |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Basis spread on variable rate (percent) |  |  |  | 3.50% |

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- Definition Amount of amortization expense attributable to debt issuance costs. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(8)) -URI http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28555-108399 + Details
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- Definition Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (b)(1) -URI http://asc.fasb.org/extlink&oid=109500613&loc=SL6031897-161870 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(16)) -URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 + Details
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- Definition Description of the frequency of periodic payments (monthly, quarterly, annual). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 470 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823 + Details
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- Definition The average effective interest rate during the reporting period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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- Definition Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
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- Definition Amount of unamortized debt discount (premium) and debt issuance costs. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (b)(2) -URI http://asc.fasb.org/extlink&oid=109500613&loc=SL6031897-161870 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28555-108399 + Details
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- Definition Amount, after accumulated amortization, of debt issuance costs related to line of credit arrangements. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section S45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=68176171&loc=SL68176184-208336 + Details
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- Definition Amount of the cost of borrowed funds accounted for as interest expense. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=6450988&loc=d3e26243-108391 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28555-108399 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (210.5-03(11)) -URI http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227 Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04.9) -URI http://asc.fasb.org/extlink&oid=116637391&loc=SL114874048-224260 + Details
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- Definition The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(16)) -URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910 + Details
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