Fair Value Measurements - Schedule of Assets and Liabilities at Fair Value on Recurring Basis (Parenthetical) (Detail) - USD ($) $ in Thousands |
3 Months Ended | 12 Months Ended |
|---|---|---|
Mar. 31, 2019 |
Dec. 31, 2018 |
|
| Recurring [Member] | Maximum [Member] | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
| Earn-out period for contingent consideration | 7 years | |
| Recurring [Member] | Minimum [Member] | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
| Earn-out period for contingent consideration | 3 years | |
| Contingent Consideration [Member] | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
| Beginning balance | $ 2,875 | $ 0 |
| Contingent consideration in connection with acquisitions | 0 | 2,674 |
| Change in fair value of contingent consideration | 48 | 201 |
| Payments of contingent consideration | 0 | 0 |
| Ending balance | $ 2,923 | $ 2,875 |
| X | ||||||||||
- Definition The specified period of time following closing during which potential contingent earn-out payments may be due per terms of the purchase agreement. 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 Amount of issuances of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Amount of increase (decrease) of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Amount of settlements of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Fair value of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|