Stock-Based Compensation (Details) (USD $)	3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended									9 Months Ended	0 Months Ended		0 Months Ended
	Dec. 29, 2012	Dec. 29, 2012	Dec. 31, 2011 Predecessor	Dec. 31, 2011 Predecessor	Dec. 29, 2012 Class A Common Stock	Mar. 31, 2012 Class A Common Stock	Feb. 27, 2012 Class A Common Stock Number Holdings, Inc.	Feb. 27, 2012 Class A Common Stock 2012 Plan Number Holdings, Inc.	Dec. 29, 2012 Class B Common Stock	Mar. 31, 2012 Class B Common Stock	Feb. 27, 2012 Class B Common Stock Number Holdings, Inc.	Feb. 27, 2012 Class B Common Stock 2012 Plan Number Holdings, Inc.	Dec. 29, 2012 Stock options Y	Feb. 27, 2012 Stock options 2012 Plan	Dec. 29, 2012 Stock options 2012 Plan Number Holdings, Inc.	Feb. 27, 2012 Stock options Class A Common Stock 2012 Plan Number Holdings, Inc.
Stock-based compensation
Number of shares authorized under the plan								74,603				74,603
Common stock, par value (in dollars per share)					$ 0.01	$ 0.01	$ 0.001		$ 0.01	$ 0.01	$ 0.001
Number of options granted		5,695											5,695			55,185
Aggregate exercise price of one share of Class A common stock and for one share of Class B common stock, together															$ 1,000
Vesting period														5 years
Expiration term														10 years
Assumptions made for estimating the fair value of stock options at the date of grant using the Black-Scholes pricing model
Weighted-average fair value of options granted (in dollars per share)													$ 369.59
Risk free interest rate (as a percent)													0.71%
Expected life													6.32
Expected stock price volatility (as a percent)													37.90%
Share-based compensation costs, additional disclosure
Total unrecognized compensation cost related to non-vested options													$ 14,800,000
Weighted-average period over which total unrecognized compensation cost related to non-vested options is expected to be recognized													4.1
Number of Shares
Options outstanding at the beginning of the period (in shares)													50,905
Granted (in shares)		5,695											5,695			55,185
Cancelled (in shares)		(1,415)											(1,415)
Outstanding at the end of the period (in shares)													55,185
Weighted Average Exercise Price
Options outstanding at the beginning of the period (in dollars per share)													$ 1,000
Granted (in dollars per share)													$ 1,000
Cancelled (in dollars per share)													$ 1,000
Outstanding at the end of the period (in dollars per share)													$ 1,000
Weighted Average Remaining Contractual Life
Weighted average remaining contractual life													8.70
Stock awards available for grant under the 2012 Plan
Available for grant at the beginning of the period (in shares)		23,698
Granted (in shares)		(5,695)											(5,695)			(55,185)
Cancelled (in shares)		1,415											1,415
Available for grant at the end of the period (in shares)	19,418	19,418
Stock-Based Compensation
Non-cash stock-based compensation expense	$ 800,000	$ 2,428,000	$ 500,000	$ 1,777,000