Marketable Securities and Fair Value Measurements - Schedule of Marketable Securities by Security Type (Detail) - USD ($)
|
12 Months Ended |
|
Dec. 31, 2015 |
Dec. 31, 2014 |
| Schedule of Available-for-sale Securities [Line Items] |
|
|
| Amortized Cost |
$ 39,989,000
|
|
| Gross Unrealized Gains |
0
|
|
| Gross Unrealized Losses |
(55,000)
|
|
| Estimated Fair Value |
39,934,000
|
$ 0
|
| Certificates of Deposit Due within One Year [Member] |
|
|
| Schedule of Available-for-sale Securities [Line Items] |
|
|
| Amortized Cost |
13,709,000
|
|
| Gross Unrealized Gains |
0
|
|
| Estimated Fair Value |
$ 13,709,000
|
|
| Marketable securities, maturity period |
1 year
|
|
| Certificates of Deposit Due after One Year through Two Years [Member] |
|
|
| Schedule of Available-for-sale Securities [Line Items] |
|
|
| Amortized Cost |
$ 1,178,000
|
|
| Gross Unrealized Gains |
0
|
|
| Estimated Fair Value |
$ 1,178,000
|
|
| Certificates of Deposit Due after One Year through Two Years [Member] | Minimum [Member] |
|
|
| Schedule of Available-for-sale Securities [Line Items] |
|
|
| Marketable securities, maturity period |
1 year
|
|
| Certificates of Deposit Due after One Year through Two Years [Member] | Maximum [Member] |
|
|
| Schedule of Available-for-sale Securities [Line Items] |
|
|
| Marketable securities, maturity period |
2 years
|
|
| United States Treasury Notes Due Within One Year [Member] |
|
|
| Schedule of Available-for-sale Securities [Line Items] |
|
|
| Amortized Cost |
$ 22,596,000
|
|
| Gross Unrealized Gains |
0
|
|
| Gross Unrealized Losses |
(47,000)
|
|
| Estimated Fair Value |
$ 22,549,000
|
|
| Marketable securities, maturity period |
1 year
|
|
| United States Treasury Notes Due after One Year through Two Years [Member] |
|
|
| Schedule of Available-for-sale Securities [Line Items] |
|
|
| Amortized Cost |
$ 2,506,000
|
|
| Gross Unrealized Gains |
0
|
|
| Gross Unrealized Losses |
(8,000)
|
|
| Estimated Fair Value |
$ 2,498,000
|
|
| United States Treasury Notes Due after One Year through Two Years [Member] | Minimum [Member] |
|
|
| Schedule of Available-for-sale Securities [Line Items] |
|
|
| Marketable securities, maturity period |
1 year
|
|
| United States Treasury Notes Due after One Year through Two Years [Member] | Maximum [Member] |
|
|
| Schedule of Available-for-sale Securities [Line Items] |
|
|
| Marketable securities, maturity period |
2 years
|
|