Stock Based Compensation - Additional Information (Detail) (USD $)	0 Months Ended	3 Months Ended	9 Months Ended					3 Months Ended	9 Months Ended	0 Months Ended	9 Months Ended		0 Months Ended
	Jun. 11, 2014	Nov. 01, 2014	Nov. 01, 2014	Nov. 02, 2013	Feb. 01, 2014	Jun. 11, 2014 After Amendment	Jun. 11, 2014 Stock Incentive Plan 2012 Before Amendment	Nov. 01, 2014 Stock Incentive Plan 2012 Stock Options	Nov. 01, 2014 Stock Incentive Plan 2012 Stock Options	Mar. 24, 2014 Stock Incentive Plan 2012 Class A common stock Stock Options Installment	Nov. 01, 2014 Stock Incentive Plan 2012 Class A common stock Stock Options Installment	Mar. 24, 2014 Stock Incentive Plan 2012 Class A common stock Stock Options	Jun. 11, 2014 Stock Incentive Plan 2012 Class A common stock Restricted Stock Director Installment	Jun. 11, 2014 Stock Incentive Plan 2012 Class A common stock Restricted Stock Director
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted			832,500							812,500	20,000
Exercise price of options		$ 13.00	$ 13.00		$ 13.31						$ 8.08	$ 12.31
Share-based compensation arrangement by share-based payment award, award vest										4	4		2
Fair value of stock option granted								$ 32,000	$ 4,300,000
Weighted average recognition period			2 years 6 months						4 years				2 years
Restricted shares granted													9,674
Number of directors to whom shares were granted														4
Restricted shares grant date fair value													300,000
Common shares authorized, increase in number of shares reserved for issuance	1,500,000
Common shares authorized						4,413,900	2,913,900
Shares available for issuance		2,366,351	2,366,351
Stock-based compensation expense		800,000	2,710,000	2,373,000
Total unrecognized stock-based compensation expense related to unvested stock options and restricted stock grants		$ 7,800,000	$ 7,800,000