Schedule I - Condensed Statements of Cash Flows (Parent Company Only) (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
CASH FLOWS FROM OPERATING ACTIVITIES:
NET INCOME	$ 165,114	$ 92,785	$ 190,559
Adjustments to reconcile net income to net cash provided by operating activities:
Net cash provided by operating activities	526,697	481,908	397,802
CASH FLOWS FROM FINANCING ACTIVITIES:
Class A common stock dividends	(121,620)	(135,108)	(70,572)
Net cash used in financing activities	(487,072)	(563,220)	(552,359)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	(8,708)	(153,601)	(205,904)
CASH AND CASH EQUIVALENTS-January 1	850,190	1,003,791	1,209,695
CASH AND CASH EQUIVALENTS-December 31	841,482	850,190	1,003,791
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Class A common stock issued/issuable in connection with business acquisitions			39,654
Parent Company [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
NET INCOME	160,212	84,309	174,917
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in earnings of subsidiaries	(103,769)	(20,598)	(109,294)
Changes in due to/from subsidiaries	65,574	71,566	4,945
Changes in other operating assets and liabilities	(7)	(89)	12
Net cash provided by operating activities	122,010	135,188	70,580
CASH FLOWS FROM FINANCING ACTIVITIES:
Class A common stock dividends	(121,620)	(135,108)	(70,572)
Net cash used in financing activities	(121,620)	(135,108)	(70,572)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	390	80	8
CASH AND CASH EQUIVALENTS-January 1	298	218	210
CASH AND CASH EQUIVALENTS-December 31	688	298	218
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Class A common stock issued/issuable in connection with business acquisitions			$ 39,654