Long Term Debt and Redeemable Preferred Stock - Interest Rate For Revolving Credit Facility (Detail) (2011 Revolving Credit Facility Due 2016 [Member])	Dec. 31, 2012
Alternate Base Rate Loans [Member]
Greater than or equal to $92,000,000	1.00%
Less than $92,000,000 but greater than or equal to $46,000,000	1.25%
Less than $46,000,000	1.50%
Eurodollar Loans [Member]
Greater than or equal to $92,000,000	2.00%
Less than $92,000,000 but greater than or equal to $46,000,000	2.25%
Less than $46,000,000	2.50%