Stockholders' Equity - Summary of Outstanding Warrants (Detail) - $ / shares	9 Months Ended
	Oct. 01, 2016	Jul. 27, 2016	Oct. 14, 2015	Mar. 25, 2015	Feb. 14, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants outstanding					61,123
Common shares, price per share					$ 30.00
(1) Warrants Related to February 2012 Financing [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants outstanding	27,963
Common Shares, Currently Exercisable	27,963
Common shares, price per share	$ 243.00
Common Shares, Expiration Date	Feb. 22, 2017
(2) Warrants Related to November 2012 Financing [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants outstanding	556
Common Shares, Currently Exercisable	556
Common shares, price per share	$ 67.50
Common Shares, Expiration Date	Nov. 26, 2016
(3) Warrants Related to December 2012 Financing [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants outstanding	1,042
Common Shares, Currently Exercisable	1,042
Common shares, price per share	$ 67.50
Common Shares, Expiration Date	Dec. 18, 2016
(4) Warrants Related to April 2013 Financing [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants outstanding	17,127
Common Shares, Currently Exercisable	17,127
Common shares, price per share	$ 81.75
Common Shares, Expiration Date	Apr. 26, 2019
(5) Warrants Related to August 2013 Financing [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants outstanding	407,825
Common Shares, Currently Exercisable	407,825
Common shares, price per share	$ 3.00
Common Shares, Expiration Date	Aug. 09, 2018
(6) Warrants Related to February 2015 Agreement [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants outstanding	3,056
Common Shares, Currently Exercisable	3,056
Common shares, price per share	$ 45.05	$ 3.00	$ 5.25	$ 24.49
Common Shares, Expiration Date	Feb. 13, 2020
(7) Warrants Related to March 2015 Financing [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants outstanding	102,093				3,056
Common Shares, Currently Exercisable	102,093
Common shares, price per share	$ 24.49				$ 45.05
Common Shares, Expiration Date	Sep. 24, 2020
(8) Warrants Related to March 2015 Financing [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants outstanding	10,209			102,093
Common Shares, Currently Exercisable	10,209
Common shares, price per share	$ 30.61			$ 24.49
Common Shares, Expiration Date	Mar. 20, 2020
(9) Warrants Related to October 2015 Financing [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants outstanding	1,355,171			10,209
Common Shares, Currently Exercisable	1,355,171
Common shares, price per share	$ 6.00			$ 30.61
Common Shares, Expiration Date	Oct. 14, 2020
(10) Warrants Related to October 2015 Financing [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants outstanding	90,345		1,806,894
Common Shares, Currently Exercisable	90,345
Common shares, price per share	$ 6.56
Common Shares, Expiration Date	Oct. 14, 2020
(11) Warrants Related to August 2016 Financing [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants outstanding	535,062		1,355,171
Common Shares, Currently Exercisable	0
Common shares, price per share	$ 3.00
Common Shares, Expiration Date	Feb. 02, 2022
(12) Warrants Related to August 2016 Financing [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants outstanding	49,939		90,345
Common Shares, Currently Exercisable	0
Common shares, price per share	$ 3.86		$ 6.5625
Common Shares, Expiration Date	Aug. 02, 2021