Supplemental Balance Sheet, Income Statement and Cash Flow Information (Details 5) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Supplemental cash flow information
Cash paid for income taxes	$ 85,044	$ 53,759	$ 58,574
Cash paid for interest, net of capitalized interest	250,045	208,212	180,731
Acquisitions of businesses:
Fair value of assets acquired		80,585	796,399
Goodwill		8,000	339,992
Liabilities assumed		(10,471)	(332,528)
Subsidiary preferred stock obligation			(69,188)
Gain on acquisition	(48,486)	(13,114)
Cash paid for acquisitions of businesses		65,000	734,675
Cash acquired in acquisitions of businesses		(9,541)	(1,045)
Cash paid for acquisition of business, net		$ 55,459	$ 733,630