Consolidated Statements Of Changes In Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Mandatory Convertible Preferred Stock [Member]	Retained Earnings [Member]	Non-Controlling Interests - Non-Redeemable [Member]	Total Equity (Permanent) [Member]	Non-controlling Interests - Redeemable (Temporary Equity) [Member]
Balance at Dec. 31, 2013		$ 185,873	$ 0	$ 578,324	$ 361,359	$ 1,125,556	$ 177,697
Balance (in shares) at Dec. 31, 2013		32,353,000	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	$ 165,709			26,322	40,672	66,994	98,715
Issuance of stock		$ 693,401	$ 166,647			860,048
Issuance of stock (in shares)		15,490,000	1,725,000
Issuance of restricted common stock (in shares)		272,000
Cancellation of restricted common stock (in shares)		(12,000)
Stock options exercised		$ 2,150				2,150
Stock options exercised (in shares)		89,000
Stock repurchased		$ (2,890)				(2,890)
Stock repurchased (in shares)		(69,000)
Share-based compensation		$ 7,388				7,388
Tax benefit related to exercise of share-based awards		2,288				2,288
Dividends paid on preferred stock				(2,239)		(2,239)
Acquisitions and other transactions impacting noncontrolling interests		762			42,119	42,881	0
Distributions to noncontrolling interests, net of capital contributions					(40,735)	(40,735)	(98,677)
Disposals and other transactions impacting noncontrolling interests		(3,350)			(520)	(3,870)	(1,219)
Balance at Sep. 30, 2014		$ 885,622	$ 166,647	602,407	402,895	2,057,571	176,516
Balance (in shares) at Sep. 30, 2014		48,123,000	1,725,000
Balance at Dec. 31, 2014	2,098,231	$ 885,393	$ 166,632	627,522	418,684	2,098,231	184,099
Balance (in shares) at Dec. 31, 2014		48,113,000	1,725,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	$ 257,781			97,374	49,895	147,269	110,512
Issuance of restricted common stock (in shares)		314,000
Cancellation of restricted common stock (in shares)		(7,000)
Stock options exercised		$ 2,356				2,356
Stock options exercised (in shares)	102,762	102,000
Stock repurchased		$ (3,684)				(3,684)
Stock repurchased (in shares)		(67,000)
Share-based compensation		$ 11,319				11,319
Tax benefit related to exercise of share-based awards		3,779				3,779
Dividends paid on preferred stock				(6,792)		(6,792)
Acquisitions and other transactions impacting noncontrolling interests		328			71,814	72,142	(645)
Distributions to noncontrolling interests, net of capital contributions					(49,345)	(49,345)	(108,574)
Disposals and other transactions impacting noncontrolling interests		(2,484)			(23,574)	(26,058)	(131)
Balance at Sep. 30, 2015	$ 2,249,217	$ 897,007	$ 166,632	$ 718,104	$ 467,474	$ 2,249,217	$ 185,261
Balance (in shares) at Sep. 30, 2015		48,455,000	1,725,000