Quarterly report pursuant to Section 13 or 15(d)

Marketable Securities and Fair Value - Summary of Company's Available-for-Sale Securities (Detail)

v3.7.0.1
Marketable Securities and Fair Value - Summary of Company's Available-for-Sale Securities (Detail) - USD ($)
$ in Thousands
Jun. 30, 2017
Dec. 31, 2016
Schedule Of Available For Sale Securities [Line Items]    
Cost Basis $ 299 $ 13,002
Unrealized Gain 0 1
Unrealized Loss 0 (3)
Fair Value 299 13,000
Money Market Funds    
Schedule Of Available For Sale Securities [Line Items]    
Cost Basis 14,103 2,746
Unrealized Gain 0 0
Unrealized Loss 0 0
Fair Value 14,103 2,746
Corporate Debt Securities    
Schedule Of Available For Sale Securities [Line Items]    
Cost Basis   4,208
Unrealized Gain   0
Unrealized Loss   (2)
Fair Value   4,206
U.S. Government Securities    
Schedule Of Available For Sale Securities [Line Items]    
Cost Basis   5,299
Unrealized Gain   1
Unrealized Loss   (1)
Fair Value   5,299
Commercial Paper    
Schedule Of Available For Sale Securities [Line Items]    
Cost Basis 299 10,966
Unrealized Gain 0 0
Unrealized Loss 0 0
Fair Value 299 10,966
Marketable Securities Including Cash Equivalents    
Schedule Of Available For Sale Securities [Line Items]    
Cost Basis 14,402 23,219
Unrealized Gain 0 1
Unrealized Loss 0 (3)
Fair Value 14,402 23,217
Less Cash Equivalents    
Schedule Of Available For Sale Securities [Line Items]    
Cost Basis 14,103 10,217
Unrealized Gain 0 0
Unrealized Loss 0 0
Fair Value $ 14,103 $ 10,217