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Debt Obligations - Narrative (Details) | 1 Months Ended | 12 Months Ended |
--- | --- | --- | ---
May 31, 2021 USD ($) engine | Mar. 31, 2020 USD ($) | Dec. 31, 2021 USD ($) | Dec. 31, 2020 USD ($) | Jun. 30, 2019 USD ($)
Long Term Debt [Line Items] |  |  |  |  |
Loss on extinguishment of debt |  |  | $ 0 | $ 4,688,000 |
Number of assets used to secure debt | engine | 2 |  |  |  |
WEST V Notes | WEST V |  |  |  |  |
Long Term Debt [Line Items] |  |  |  |  |
Debt instrument, face amount |  | $ 366,200,000 |  |  |
WEST V Series A Notes |  |  |  |  |
Long Term Debt [Line Items] |  |  |  |  |
Fixed rate |  |  | 3.23% |  |
WEST V Series A Notes | WEST V |  |  |  |  |
Long Term Debt [Line Items] |  |  |  |  |
Debt instrument, face amount |  | $ 303,000,000 |  |  |
Fixed rate |  | 3.228% |  |  |
Debt term |  | 8 years |  |  |
Notes issue price, percentage of par |  | 99.99859% |  |  |
WEST V Series B Notes |  |  |  |  |
Long Term Debt [Line Items] |  |  |  |  |
Fixed rate |  |  | 4.21% |  |
WEST V Series B Notes | WEST V |  |  |  |  |
Long Term Debt [Line Items] |  |  |  |  |
Debt instrument, face amount |  | $ 42,100,000 |  |  |
Fixed rate |  | 4.212% |  |  |
Debt term |  | 8 years |  |  |
Notes issue price, percentage of par |  | 99.99493% |  |  |
WEST V Series C Notes |  |  |  |  |
Long Term Debt [Line Items] |  |  |  |  |
Fixed rate |  |  | 6.66% |  |
WEST V Series C Notes | WEST V |  |  |  |  |
Long Term Debt [Line Items] |  |  |  |  |
Debt instrument, face amount |  | $ 21,100,000 |  |  |
Fixed rate |  | 6.657% |  |  |
Debt term |  | 8 years |  |  |
Notes issue price, percentage of par |  | 99.99918% |  |  |
WEST VI Notes | WEST VI |  |  |  |  |
Long Term Debt [Line Items] |  |  |  |  |
Debt instrument, face amount | $ 336,700,000 |  |  |  |
WEST VI Series A Notes |  |  |  |  |
Long Term Debt [Line Items] |  |  |  |  |
Fixed rate |  |  | 3.10% |  |
WEST VI Series A Notes | WEST V |  |  |  |  |
Long Term Debt [Line Items] |  |  |  |  |
Fixed rate | 3.104% |  |  |  |
Debt term | 8 years |  |  |  |
Notes issue price, percentage of par | 99.99481% |  |  |  |
WEST VI Series A Notes | WEST VI |  |  |  |  |
Long Term Debt [Line Items] |  |  |  |  |
Debt instrument, face amount | $ 278,600,000 |  |  |  |
WEST VI Series B Notes |  |  |  |  |
Long Term Debt [Line Items] |  |  |  |  |
Fixed rate |  |  | 5.44% |  |
WEST VI Series B Notes | WEST V |  |  |  |  |
Long Term Debt [Line Items] |  |  |  |  |
Fixed rate | 5.438% |  |  |  |
Debt term | 8 years |  |  |  |
Notes issue price, percentage of par | 99.99996% |  |  |  |
WEST VI Series B Notes | WEST VI |  |  |  |  |
Long Term Debt [Line Items] |  |  |  |  |
Debt instrument, face amount | $ 38,700,000 |  |  |  |
WEST VI Series C Notes |  |  |  |  |
Long Term Debt [Line Items] |  |  |  |  |
Fixed rate |  |  | 7.39% |  |
WEST VI Series C Notes | WEST V |  |  |  |  |
Long Term Debt [Line Items] |  |  |  |  |
Fixed rate | 7.385% |  |  |  |
Debt term | 8 years |  |  |  |
Notes issue price, percentage of par | 99.99869% |  |  |  |
WEST VI Series C Notes | WEST VI |  |  |  |  |
Long Term Debt [Line Items] |  |  |  |  |
Debt instrument, face amount | $ 19,400,000 |  |  |  |
WEST II Notes |  |  |  |  |
Long Term Debt [Line Items] |  |  |  |  |
Loss on extinguishment of debt |  | $ 4,700,000 |  |  |
Revolving credit facility | Revolving credit facility |  |  |  |  |
Long Term Debt [Line Items] |  |  |  |  |
Line of credit facility, maximum borrowing capacity |  |  | $ 1,000,000,000 |  | $ 1,000,000,000
Line of credit facility, maximum borrowing capacity under accordion feature |  |  | 1,300,000,000 |  |
Line of credit facility, remaining borrowing capacity |  |  | $ 410,000,000 | $ 223,000,000 |

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