Selected Quarterly Financial Data - Summary of Quarterly Financial Data (Detail) - USD ($) $ / shares in Units, $ in Thousands |
3 Months Ended | 12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2017 |
Sep. 30, 2017 |
Jun. 30, 2017 |
Mar. 31, 2017 |
Dec. 31, 2016 |
Sep. 30, 2016 |
Jun. 30, 2016 |
Mar. 31, 2016 |
Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
|
| Quarterly Financial Information Disclosure [Abstract] | |||||||||||
| Total revenue | $ 27,095 | $ 26,402 | $ 28,275 | $ 23,800 | $ 19,862 | $ 19,008 | $ 21,845 | $ 20,483 | $ 105,573 | $ 81,198 | $ 58,679 |
| Total expenses | 25,788 | 25,298 | 24,159 | 20,697 | 18,840 | 16,951 | 19,110 | 17,509 | 95,942 | 72,411 | 50,429 |
| Income before equity method investments | 1,307 | 1,104 | 4,116 | 3,103 | 1,022 | 2,057 | 2,735 | 2,974 | 9,631 | 8,787 | 8,250 |
| Income (loss) from equity method investments | 2,866 | 6,876 | 8,377 | 4,171 | 3,433 | 1,331 | 1,076 | 270 | 22,289 | 6,110 | (98) |
| Income before income taxes | 4,173 | 7,980 | 12,493 | 7,274 | 4,455 | 3,388 | 3,811 | 3,244 | 31,920 | 14,897 | 8,152 |
| Income tax (expense) benefit | (766) | (5) | (83) | (32) | (18) | (41) | (36) | (47) | (885) | (141) | (118) |
| Net income (loss) | 3,407 | 7,975 | 12,410 | 7,242 | 4,437 | 3,347 | 3,775 | 3,197 | 31,035 | 14,756 | 8,034 |
| Net income (loss) attributable to controlling shareholders | $ 3,383 | $ 7,933 | $ 12,340 | $ 7,199 | $ 4,408 | $ 3,329 | $ 3,747 | $ 3,169 | $ 30,856 | $ 14,652 | $ 7,958 |
| Basic and diluted earnings per common share | $ 0.06 | $ 0.14 | $ 0.23 | $ 0.14 | $ 0.09 | $ 0.07 | $ 0.09 | $ 0.07 | |||
| X | ||||||||||
- Definition Sum of operating and non-operating costs including investment interest expense, compensation and benefits and general and administrative. No definition available.
|
| X | ||||||||||
- Definition The amount of net income or loss for the period per each share in instances when basic and diluted earnings per share are the same amount and reported as a single line item on the face of the financial statements. Basic earnings per share is the amount of net income or loss for the period per each share of common stock or unit outstanding during the reporting period. Diluted earnings per share includes the amount of net income or loss for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period. No definition available.
|
| X | ||||||||||
- Definition Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of income (loss) from continuing operations before deduction of income tax expense (benefit) and income (loss) attributable to noncontrolling interest, and addition of income (loss) from equity method investments. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition This item represents the entity's proportionate share for the period of the net income (loss) of its investee (such as unconsolidated subsidiaries and joint ventures) to which the equity method of accounting is applied. This item includes income or expense related to stock-based compensation based on the investor's grant of stock to employees of an equity method investee. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The portion of profit or loss for the period, net of income taxes, which is attributable to the parent. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss). Reference 1: http://www.xbrl.org/2003/role/presentationRef
|