Stockholders' Equity - Additional Information (Detail)				1 Months Ended															12 Months Ended
	Jul. 10, 2015	Jul. 08, 2015 USD ($) shares	Jun. 18, 2015 USD ($) $ / shares shares	Dec. 31, 2016 USD ($) $ / shares shares	Nov. 30, 2016 USD ($) $ / shares shares	Sep. 30, 2016 USD ($) $ / shares shares	Aug. 31, 2016 USD ($) $ / shares shares	Jun. 30, 2016 USD ($) $ / shares shares	May 31, 2016 USD ($) $ / shares shares	Feb. 29, 2016 USD ($) $ / shares shares	Jul. 31, 2015 USD ($) shares	Jun. 30, 2015 USD ($) shares	Apr. 30, 2015 USD ($) $ / shares shares	Mar. 31, 2015 $ / shares shares	Apr. 30, 2014 USD ($) $ / shares shares	Mar. 31, 2014 shares	Dec. 31, 2013 USD ($) shares	Jun. 30, 2013 USD ($) $ / shares shares	Dec. 31, 2016 USD ($) $ / shares shares	Dec. 31, 2015 USD ($) $ / shares shares	Dec. 31, 2014 USD ($) Director $ / shares shares	Nov. 30, 2015 USD ($)	Dec. 31, 2010 USD ($) $ / shares
Class Of Stock [Line Items]
Total amount authorized for repurchase | $																						$ 50,000,000
Repurchase of common stock, shares				124,286	439,618	30,000	335,440	582,400	346,200	300,000									2,157,944	0
Repurchase of common stock, par value | $ / shares				$ 6.45	$ 7.14	$ 7.40	$ 7.01	$ 7.56	$ 6.77	$ 8.50									$ 7.33
Repurchase of common stock, value | $																			$ 15,847,000	$ 4,798,000
Broker commissions on the repurchases | $																			36,000
Remained authorized shares for repurchase | $				$ 34,200,000	$ 35,000,000	$ 38,100,000	$ 38,400,000	$ 40,700,000	$ 45,100,000	$ 47,500,000									$ 34,200,000
Forward stock split of its outstanding common stock	1.8515
Common stock, shares authorized				500,000,000								100,000,000							500,000,000	500,000,000
Proceeds from issuance of common stock net of issuance costs | $		$ 7,000,000										$ 71,000,000
Common stock, shares issued				81,983,937							9,531,200								81,983,937	81,311,686
Proceeds from sale of common stock | $											$ 221,500,000
Underwriting discounts, commissions and offering expenses | $											$ 16,800,000
Stock issued to offset the loan				81,983,937							9,531,200								81,983,937	81,311,686
Proceeds from exercise of warrants | $																			$ 52,000	$ 7,348,000	$ 0
Derivative liability | $																	$ 19,000			$ 0	$ 177,000
Common stock, par value | $ / shares				$ 0.0001															$ 0.0001	$ 0.0001	$ 0.0001
Common stock, shares outstanding				81,983,937															81,983,937	81,311,686
Common Stock Warrant
Class Of Stock [Line Items]
Derivative liability | $													$ 1,500,000								$ 200,000		$ 400,000
Inex Bio Inc
Class Of Stock [Line Items]
Stock price of warrants | $ / shares														$ 2.00
Warrants issued to purchase common shares														3,202,592
Proceeds from exercise of warrants | $													$ 6,400,000
Officers
Class Of Stock [Line Items]
Forward stock split of its outstanding common stock																			1
2013 Promissory Note
Class Of Stock [Line Items]
Convertible notes payable current | $																		$ 1,000,000
Private Placement
Class Of Stock [Line Items]
Issuance of common stock, Shares												3,698,695
Proceeds from issuance of common stock net of issuance costs | $											$ 17,000,000
Issuance costs | $												$ 28,000
Common stock, shares issued		364,638									680,000
Stock issued to offset the loan		364,638									680,000
Common Class A
Class Of Stock [Line Items]
Repurchase of common stock, shares			249,952																0	249,952
Repurchase of common stock, par value | $ / shares			$ 19.20
Repurchase of common stock, value | $			$ 4,800,000																$ 0	$ 0
Forward stock split of its outstanding common stock												1.00
Issuance of common stock, Shares																					30,809,800
Issuance of restricted stock, Shares																					129,605
Conversion of debt and payables to Class A common stock, Shares																					1,522,799
Conversion of Class A common stock to common stock, Shares																				(65,900,303)
Issuance of stock for placement agent in shares																					3,087,324
Stock price of warrants | $ / shares																		$ 2.44
Conversion of stock for placement agent in shares and exchange of warrant																		193,413
Debt instrument, percentage of common stock																		4.00%
Issuance of placement agent warrant associated with 2014 Securities Purchase Agreement																		199,341
Common Class A | Common Stock Warrant
Class Of Stock [Line Items]
Stock price of warrants | $ / shares													$ 1.76
Warrant exercised and shares issued													114,822
Warrant exercisable price per share | $ / shares																							$ 2.44
Warrant expiration date																			Feb. 29, 2020
Period of warrant holder protected against down-round financing after reverse merger																			2 years
Percentage of shareholders consent																			66.67%
Common Class A | Private Placement
Class Of Stock [Line Items]
Issuance of common stock, Shares																				0
Common Class A | Private Placement One | Sorrento
Class Of Stock [Line Items]
Issuance of common stock, Shares																					4,557,537
Common stock issued, par value | $ / shares																					$ 1.76
Proceeds from issuance of common stock gross of issuance costs | $																					$ 8,000,000
Common Class A | Private Placement Two
Class Of Stock [Line Items]
Issuance of common stock, Shares																					26,252,262
Common stock issued, par value | $ / shares																					$ 1.89
Proceeds from issuance of common stock gross of issuance costs | $																					$ 49,500,000
Number of board of directors | Director																					9
Common Class A | Private Placement Two | Sorrento
Class Of Stock [Line Items]
Issuance of common stock, Shares																					1,060,789
Issuance costs | $																					$ 200,000
Proceeds from issuance of common stock gross of issuance costs | $																					2,000,000
Common Class A | 2014 Securities Purchase Agreement
Class Of Stock [Line Items]
Broker commissions on the repurchases | $																					$ 45,000
Stock issued for placement agent commission																					3,087,324
Common Class A | 2014 Securities Purchase Agreement | Outstanding Warrants
Class Of Stock [Line Items]
Issuance of common stock, Shares															1,245,881
Conversion of stock for placement agent in shares and exchange of warrant															193,413
Issuance of placement agent warrant associated with 2014 Securities Purchase Agreement															199,341
Common Class A | 2014 Securities Purchase Agreement | Outstanding Warrants | Founders License Agreement March 2014 Amendment
Class Of Stock [Line Items]
Conversion of warrant to purchase common stock																156,109
Common Class A | 2014 Securities Purchase Agreement | Employee Stock Option | Founders License Agreement March 2014 Amendment
Class Of Stock [Line Items]
Conversion of options to purchase common stock																740,600
Common Class A | 2014 Securities Purchase Agreement | 2013 Promissory Note | Outstanding Warrants
Class Of Stock [Line Items]
Common stock issued for conversion of debt															192,865
Common Class A | 2013 Securities Purchase Agreement
Class Of Stock [Line Items]
Conversion of Class A common stock to common stock, Shares																			406,048
Common Class A | 2013 Securities Purchase Agreement | 2013 Converted Creditors
Class Of Stock [Line Items]
Common stock issued for conversion of debt																			389,437
Common Stock Class Undefined
Class Of Stock [Line Items]
Common stock, shares authorized																					80,000,000
Common Class B
Class Of Stock [Line Items]
Repurchase of common stock, shares																			0	0
Repurchase of common stock, value | $																			$ 0	$ 0
Stock approved for conversion to Class A common stock.																					8,295,402
Issuance of common stock, Shares																					0
Common stock, shares issued																	1,681,099				5,851,152
Issuance of restricted stock, Shares																					0
Conversion of debt and payables to Class A common stock, Shares																					0
Conversion of Class A common stock to common stock, Shares																				0
Issuance of stock for placement agent in shares															763,151	763,151					763,151
Stock issued to offset the loan																	1,681,099				5,851,152
Debt instrument, percentage of common stock																		2.50%
Common Class B | Officers
Class Of Stock [Line Items]
Restricted stock purchase agreements, shares																	7,532,251
Common Class B | Private Placement
Class Of Stock [Line Items]
Issuance of common stock, Shares																				0
Series B Preferred Stock
Class Of Stock [Line Items]
Forward stock split of its outstanding common stock																			0.067
Stock approved for conversion to Class A common stock.																					9,502,898
Common stock, conversion basis																			In March 2014, the Company entered into a definitive merger and share exchange agreement pursuant to which the Company redomesticated from the State of Illinois to the State of Delaware and the Illinois Company ceased to exist (the Redomestication). In connection with the Redomestication, the holders of Class A and Class B common stock received one share of Class A and Class B common stock of the Delaware Company, respectively, in exchange for fifteen shares of the Illinois Company. The holders of Series B preferred stock received one share of Series B preferred stock of the Delaware Company in exchange for one share of the Illinois Company. The holders of any options, warrants or other securities are subject to adjustment based on the ratio of 1 for 15. All share numbers and per share prices in the accompanying consolidated financial statements have been adjusted to reflect the 1 for 15 exchange.
Series C Preferred Stock
Class Of Stock [Line Items]
Stock approved for conversion to Class A common stock.																					5,754,984
Series C Preferred Stock | 2014 Securities Purchase Agreement
Class Of Stock [Line Items]
Issuance of common stock, Shares															4,983,526
Proceeds from issuance of common stock net of issuance costs | $															$ 6,500,000
Conversion of Promissory Note															0.25
Warrant term															3 years
Series C Preferred Stock | 2014 Securities Purchase Agreement | 2013 Promissory Note
Class Of Stock [Line Items]
Common stock issued for conversion of debt															771,458
Stock price of warrants | $ / shares															$ 1.62
Series B Common Stock and Series C Preferred Stock
Class Of Stock [Line Items]
Forward stock split of its outstanding common stock																					1.00
Series B Preferred Stock
Class Of Stock [Line Items]
Stock approved for conversion to Class A common stock.																					5,132,548
Minimum
Class Of Stock [Line Items]
Repurchase of common stock, par value | $ / shares																			$ 6.05
Common stock, shares authorized											100,000,000
Maximum
Class Of Stock [Line Items]
Repurchase of common stock, par value | $ / shares																			$ 8.50
Common stock, shares authorized											500,000,000