Stockholders' Equity Issuance of Common Stock in Connection with Acquisition of CYS Investments, Inc. (Details) - USD ($) $ in Millions |
1 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Mar. 22, 2019 |
Jul. 31, 2018 |
Jun. 30, 2019 |
Jun. 30, 2018 |
|
| Class of Stock [Line Items] | ||||
| Aggregate cash consideration exchanged for shares of CYS common stock | $ 15.0 | |||
| Common Stock [Member] | ||||
| Class of Stock [Line Items] | ||||
| Number of shares of stock issued during period (in shares) | 18,000,000 | 72,600,000 | 24,390,456 | 12,468 |
| X | ||||||||||
- Definition Aggregate cash consideration exchanged for shares of CYS common stock. No definition available.
|
| X | ||||||||||
- 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. No definition available.
|
| X | ||||||||||
- Definition Number of new stock issued during the period. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Details
|