Schedule V - Valuation and Qualifying Accounts (Detail) (Allowance for Uncollectible Accounts Receivable [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Allowance for Uncollectible Accounts Receivable [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of period	$ 55,163	$ 15,293	$ 8,116
Charged to costs and expenses	24,256	72,788	31,203
Deductions	71,733	32,918	24,026
Balance at end of period	$ 7,686	$ 55,163	$ 15,293