Consolidated Statements Of Changes In Equity (USD $)	Total	Common Stock Including Additional Paid in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]	Noncontrolling Interest Nonredeemable Member [Member]	Total Equity [Member]	Non-Controlling Interests - Redeemable (Temporary Equity) [Member]
Balance at Dec. 31, 2010		$ 171,522,000	$ 393,061,000	$ (515,000)	$ 12,799,000	$ 576,867,000	$ 147,740,000
Balance (in shares) at Dec. 31, 2010		31,040,000
Issuance of restricted common stock (in shares)		277,000
Cancellation of restricted common stock		(525,000)				(525,000)
Cancellation of restricted common stock (in shares)		(23,000)
Stock options exercised		4,760,000				4,760,000
Stock options exercised (in shares)		244,000
Stock repurchased	(6,185,000)	(6,185,000)				(6,185,000)
Stock repurchased (in shares)	(248,100)	(248,000)
Share-based compensation expense	4,762,000	4,762,000				4,762,000
Tax benefit related to exercise of stock options		169,000				169,000
Net earnings (loss)	138,622,000		36,449,000		5,611,000	42,060,000	96,562,000
Distributions to noncontrolling interests, net of capital contributions					(5,411,000)	(5,411,000)	(97,952,000)
Purchase of noncontrolling interest, value		(296,000)				(296,000)	(788,000)
Sale of noncontrolling interest, value		(1,427,000)				(1,427,000)	1,772,000
Acquisitions and other transactions impacting noncontrolling interests					87,294,000	87,294,000	20,318,000
Gain on interest rate swap, net of income tax expense				515,000		515,000
Balance at Sep. 30, 2011		172,780,000	429,510,000	0	100,293,000	702,583,000	167,652,000
Balance (in shares) at Sep. 30, 2011		31,290,000
Balance at Dec. 31, 2011	748,467,000	173,187,000	443,058,000	0	132,222,000	748,467,000	170,636,000
Balance (in shares) at Dec. 31, 2011		31,284,000
Issuance of restricted common stock (in shares)		281,000
Cancellation of restricted common stock (in shares)		(2,000)
Stock options exercised		11,928,000				11,928,000
Stock options exercised (in shares)	579,598	580,000
Stock repurchased	(11,838,000)	(13,101,000)				(13,101,000)
Stock repurchased (in shares)	(415,084)	(464,000)
Share-based compensation expense	5,119,000	5,119,000				5,119,000
Tax benefit related to exercise of stock options		1,318,000				1,318,000
Net earnings (loss)	164,249,000		45,749,000		18,578,000	64,327,000	99,922,000
Distributions to noncontrolling interests, net of capital contributions					(20,192,000)	(20,192,000)	(102,804,000)
Purchase of noncontrolling interest, value		166,000			(289,000)	(123,000)	(81,000)
Sale of noncontrolling interest, value		(2,277,000)			3,555,000	1,278,000
Acquisitions and other transactions impacting noncontrolling interests					2,212,000	2,212,000	7,038,000
Disposals and other transactions impacting noncontrolling interests		(369,000)				(369,000)	176,000
Balance at Sep. 30, 2012	$ 800,864,000	$ 175,971,000	$ 488,807,000	$ 0	$ 136,086,000	$ 800,864,000	$ 174,887,000
Balance (in shares) at Sep. 30, 2012		31,679,000