Investments and Fair Value Measurements - Schedule of Investments (Detail) - USD ($) $ in Thousands |
Dec. 31, 2015 |
Dec. 31, 2014 |
---|---|---|
Schedule of Held-to-maturity Securities [Line Items] | ||
Held-to-Maturity debt instruments | $ 23,689 | $ 13,990 |
Federal Agency [Member] | ||
Schedule of Held-to-maturity Securities [Line Items] | ||
Held-to-Maturity debt instruments | $ 23,689 | $ 13,990 |