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		$ 578,324	$ 361,359	$ 1,125,556	$ 177,697
Balance (in shares) at Dec. 31, 2013		32,353,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	$ 128,286			36,156	26,788	62,944	65,342
Issuance of restricted common stock (in shares)		225,000
Cancellation of restricted common stock (in shares)		(7,000)
Stock options exercised		$ 1,646				1,646
Stock options exercised (in shares)		69,000
Stock repurchased		$ (2,857)				(2,857)
Stock repurchased (in shares)		(68,000)
Share-based compensation		$ 4,964				4,964
Tax benefit related to exercise of share based awards		2,090				2,090
Acquisitions and other transactions impacting noncontrolling interests		305			19,435	19,740	0
Distributions to noncontrolling interests, net of capital contributions					(26,846)	(26,846)	(65,134)
Disposals and other transactions impacting noncontrolling interests		(2,199)			(1,943)	(4,142)	(842)
Balance at Jun. 30, 2014		$ 189,822	$ 0	614,480	378,793	1,183,095	177,063
Balance (in shares) at Jun. 30, 2014		32,572,000	0
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	$ 159,502			54,713	33,117	87,830	71,672
Issuance of restricted common stock (in shares)		314,000
Cancellation of restricted common stock (in shares)		(7,000)
Stock options exercised		$ 2,080				2,080
Stock options exercised (in shares)	90,012	90,000
Stock repurchased		$ (3,684)				(3,684)
Stock repurchased (in shares)		(67,000)
Share-based compensation		$ 7,592				7,592
Tax benefit related to exercise of share based awards		3,533				3,533
Dividends paid on preferred stock				(4,528)		(4,528)
Acquisitions and other transactions impacting noncontrolling interests		599			59,888	60,487	(408)
Distributions to noncontrolling interests, net of capital contributions					(30,989)	(30,989)	(69,819)
Disposals and other transactions impacting noncontrolling interests		(2,194)			2,229	35	(367)
Balance at Jun. 30, 2015	$ 2,220,587	$ 893,319	$ 166,632	$ 677,707	$ 482,929	$ 2,220,587	$ 185,177
Balance (in shares) at Jun. 30, 2015		48,443,000	1,725,000