Fair Value Measurements - Summary of Changes in Fair Value of Company's Level 3 Assets and Liabilities (Parenthetical) (Detail) - USD ($) $ in Thousands |
12 Months Ended | ||
---|---|---|---|
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
|
Equities [Member] | |||
Fair Value of Assets and Liabilities Measured on Recurring Basis Unobservable Input Reconciliation [Line Items] | |||
Net unrealized gains | $ 243 | $ 14 | $ 19 |
Contingent Consideration Liability [Member] | Edgewater Acquisition [Member] | |||
Fair Value of Assets and Liabilities Measured on Recurring Basis Unobservable Input Reconciliation [Line Items] | |||
Net unrealized losses | 2,658 | ||
Net realized losses | $ 30,067 |