Long-Term Debt (Parenthetical) (Detail) (2.50% to 10.9% Notes Payable to Sellers and Other Third Parties)	12 Months Ended
	Dec. 31, 2012
2.50% to 10.9% Notes Payable to Sellers and Other Third Parties
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage Rate Range, Minimum	2.50%
Debt Instrument, Interest Rate, Stated Percentage Rate Range, Maximum	10.90%
Debt Instrument, Maturity Date Range, Start	2014
Debt Instrument, Maturity Date Range, End	2036