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Debt Obligations (Details) $ in Thousands |  |  |  |  | 12 Months Ended |  |
--- | --- | --- | --- | --- | --- | --- | ---
Aug. 04, 2017 USD ($) item | Mar. 25, 2015 USD ($) | Jul. 16, 2014 USD ($) | Jan. 10, 2014 engine | Dec. 31, 2017 USD ($) | Dec. 31, 2016 USD ($) | Dec. 31, 2015 USD ($) | Jun. 30, 2016 USD ($) item | Apr. 30, 2016 USD ($)
Long Term Debt |  |  |  |  |  |  |  |  |
Maturity term | 10 years |  |  |  |  |  |  |  |
Maintenance Reserves |  |  |  |  | $ 75,889 | $ 71,602 |  |  |
Percentage of the funding for the purchase of a corporate aircraft |  |  |  |  | 100.00% |  |  |  |
Principal outstanding repayable |  |  |  |  |  |  |  |  |
2018 |  |  |  |  | $ 48,401 |  |  |  |
2019 |  |  |  |  | 38,537 |  |  |  |
2020 |  |  |  |  | 38,137 |  |  |  |
2021 |  |  |  |  | 529,374 |  |  |  |
2022 |  |  |  |  | 190,889 |  |  |  |
Thereafter |  |  |  |  | 258,405 |  |  |  |
Total |  |  |  |  | 1,103,743 | 913,703 |  |  |
Less: unamortized debt issuance costs |  |  |  |  | (18,338) | (13,448) |  |  |
Notes payable |  |  |  |  | $ 1,085,405 | 900,255 |  |  |
Gains (Losses) on Extinguishment of Debt |  |  |  |  |  | $ (137) | $ 1,151 |  |
One-month LIBOR |  |  |  |  |  |  |  |  |
Long Term Debt |  |  |  |  |  |  |  |  |
One-month LIBOR rate (as a percent) |  |  |  |  | 1.57% | 0.77% |  |  |
WEST III |  |  |  |  |  |  |  |  |
Long Term Debt |  |  |  |  |  |  |  |  |
Number of series notes | item | 2 |  |  |  |  |  |  |  |
Maintenance Reserves |  |  |  |  | $ 10,000 |  |  |  |
Credit facility at a floating rate of interest of one-month LIBOR plus 1.50% and maturity date of April 2021 |  |  |  |  |  |  |  |  |
Long Term Debt |  |  |  |  |  |  |  |  |
Maximum borrowing capacity under credit facility |  |  |  |  | $ 890,000 |  |  |  |
Fixed rate (as a percent) |  |  |  |  | 1.50% |  |  |  |
Principal outstanding repayable |  |  |  |  |  |  |  |  |
Total |  |  |  |  | $ 491,000 | $ 608,000 |  |  |
WEST III |  |  |  |  |  |  |  |  |
Long Term Debt |  |  |  |  |  |  |  |  |
Line of credit facility outstanding amount |  |  |  |  | 330,700 |  |  |  |
WEST III Series A 2017-1 term notes payable at a fixed rate of interest of 4.69%, maturing in August 2042. Secured by engines |  |  |  |  |  |  |  |  |
Principal outstanding repayable |  |  |  |  |  |  |  |  |
Total |  |  |  |  | $ 289,295 |  |  |  |
WEST III Series A 2017-1 term notes payable at a fixed rate of interest of 4.69%, maturing in August 2042. Secured by engines | WEST III |  |  |  |  |  |  |  |  |
Long Term Debt |  |  |  |  |  |  |  |  |
Fixed rate (as a percent) |  |  |  |  | 4.69% |  |  |  |
Aggregate principal amount | $ 293,700 |  |  |  |  |  |  |  |
WEST III Series B 2017-1 term notes payable at a fixed rate of interest of 6.36%, maturing in August 2042. Secured by engines |  |  |  |  |  |  |  |  |
Principal outstanding repayable |  |  |  |  |  |  |  |  |
Total |  |  |  |  | $ 41,370 |  |  |  |
WEST III Series B 2017-1 term notes payable at a fixed rate of interest of 6.36%, maturing in August 2042. Secured by engines | WEST III |  |  |  |  |  |  |  |  |
Long Term Debt |  |  |  |  |  |  |  |  |
Fixed rate (as a percent) |  |  |  |  | 6.36% |  |  |  |
Aggregate principal amount | $ 42,000 |  |  |  |  |  |  |  |
WEST II Series 2012-A term notes payable at a fixed rate of interest of 5.50%, maturing in September 2037, secured by engines |  |  |  |  |  |  |  |  |
Principal outstanding repayable |  |  |  |  |  |  |  |  |
Total |  |  |  |  | $ 259,022 | 279,541 |  |  |
WEST II Series 2012-A term notes payable at a fixed rate of interest of 5.50%, maturing in September 2037, secured by engines | WEST II |  |  |  |  |  |  |  |  |
Long Term Debt |  |  |  |  |  |  |  |  |
Fixed rate (as a percent) |  |  |  |  | 5.50% |  |  |  |
Note payable at fixed interest rates ranging from 2.60% to 2.97%, maturing in July 2024. Secured by an aircraft |  |  |  |  |  |  |  |  |
Long Term Debt |  |  |  |  |  |  |  |  |
Number of series notes | item |  |  |  |  |  |  |  | 2 |
Aggregate principal amount |  |  | $ 13,400 |  |  |  |  | $ 4,700 |
Maturity term |  |  | 10 years |  |  |  |  |  |
Initial term for interest payment |  |  |  |  | 5 years |  |  |  |
Principal outstanding repayable |  |  |  |  |  |  |  |  |
Total |  |  |  |  | $ 12,720 | 14,453 |  |  |
Note payable at fixed interest rates ranging from 2.60% to 2.97%, maturing in July 2024. Secured by an aircraft | Minimum |  |  |  |  |  |  |  |  |
Long Term Debt |  |  |  |  |  |  |  |  |
Fixed rate (as a percent) |  |  |  |  | 2.60% |  |  |  |
Note payable at fixed interest rates ranging from 2.60% to 2.97%, maturing in July 2024. Secured by an aircraft | Maximum |  |  |  |  |  |  |  |  |
Long Term Debt |  |  |  |  |  |  |  |  |
Fixed rate (as a percent) |  |  |  |  | 2.97% |  |  |  |
Note payable at a variable interest rate of 2.25%, maturing in January 2018, secured by engines |  |  |  |  |  |  |  |  |
Long Term Debt |  |  |  |  |  |  |  |  |
Fixed rate (as a percent) |  |  |  |  | 2.25% |  |  |  |
Maturity term |  |  |  | 4 years |  |  |  |  |
Principal outstanding repayable |  |  |  |  |  |  |  |  |
Total |  |  |  |  | $ 10,336 | 11,709 |  |  |
Number of engines pledged as collateral | engine |  |  |  | 3 |  |  |  |  |
Note payable at a variable interest rate of 2.25%, maturing in January 2018, secured by engines | One-month LIBOR |  |  |  |  |  |  |  |  |
Long Term Debt |  |  |  |  |  |  |  |  |
Fixed rate (as a percent) |  |  |  | 2.25% |  |  |  |  |
Revolving credit facility |  |  |  |  |  |  |  |  |
Long Term Debt |  |  |  |  |  |  |  |  |
Maximum borrowing capacity under credit facility |  |  |  |  |  |  |  |  | $ 890,000
Amount of debt available under accordion feature |  |  |  |  |  |  |  |  | 1,000,000
Line of credit facility outstanding amount |  |  |  |  | 491,000 |  |  |  |
Principal outstanding repayable |  |  |  |  |  |  |  |  |
Remaining borrowing capacity available |  |  |  |  | $ 399,000 | $ 282,000 |  |  |
Maximum borrowing capacity under credit facility before amendment |  |  |  |  |  |  |  |  | $ 700,000
Term notes | WOLF |  |  |  |  |  |  |  |  |
Principal outstanding repayable |  |  |  |  |  |  |  |  |
Loan Paid off |  | $ 23,100 |  |  |  |  |  |  |
Discount (in percentage) |  | 5.00% |  |  |  |  |  |  |
Gains (Losses) on Extinguishment of Debt |  |  |  |  |  |  | $ 1,200 |  |

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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/presentationRef -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://www.xbrl.org/2003/role/presentationRef -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=6879938&loc=d3e572229-122910 Reference 3: http://www.xbrl.org/2003/role/presentationRef -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 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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