Shareholders' Equity (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	1 Months Ended	3 Months Ended		6 Months Ended
	Dec. 27, 2012	Apr. 04, 2013	Dec. 06, 2012	Mar. 02, 2013	Feb. 25, 2012
Components Of Shareholders Equity [Line Items]
Cash dividends				$ 37,855	$ 31,522
Dividend declared, per share		$ 0.30	$ 0.30
Dividend payable date		Apr. 30, 2013	Dec. 27, 2012
Dividend record date		Apr. 16, 2013	Dec. 17, 2012
Dividend payout	18,948	18,988
Class A common stock shares repurchase amount				$ 3,629
Maximum number of shares that may yet be repurchased				4,384
MSC Stock Repurchase Plan [Member]
Components Of Shareholders Equity [Line Items]
Class A common stock shares repurchased				50