Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cash flows used for operating activities:
Net income	$ 273,352	$ 208,843	$ 165,612
Reconciliation of net income to net cash provided by (used in) operating activities:
Depreciation and amortization	79,853	78,810	82,832
Equity in earnings from real estate ventures	(31,343)	(23,857)	(6,385)
Gain on sale of assets	(2,555)	0	0
Operating distributions from real estate ventures	13,672	10,641	593
Provision for loss on receivables and other assets	8,715	6,586	10,273
Amortization of deferred compensation	22,703	32,276	34,002
Accretion of interest on deferred business acquisition obligations	7,837	17,744	19,503
Amortization of debt issuance costs	4,437	4,375	4,384
Change in:
Receivables	(267,550)	(90,495)	(190,620)
Prepaid expenses and other assets	(45,014)	(33,986)	3,320
Deferred tax assets, net	28,058	(12,600)	(9,270)
Excess tax benefit from share-based payment arrangements	(3,579)	(3,323)	(17,999)
Accounts payable, accrued liabilities and accrued compensation	204,581	132,684	115,093
Net cash provided by operating activities	293,167	327,698	211,338
Cash flows used for investing activities:
Net capital additions - property and equipment	(110,684)	(94,758)	(91,538)
Proceeds from the sale of assets	13,604	0	0
Business acquisitions	(57,544)	(27,706)	(251,787)
Capital contributions and advances to real estate ventures	(37,217)	(106,322)	(71,027)
Distributions, repayments of advances and sale of investments	27,629	77,534	25,036
Net cash used in investing activities	(164,212)	(151,252)	(389,316)
Cash flows from financing activities:
Proceeds from borrowings under credit facilities	1,957,791	1,690,142	1,550,590
Repayments of borrowings under credit facilities	(1,979,500)	(2,017,000)	(1,248,700)
Issuance of senior notes, net	0	272,396	0
Payment of deferred business acquisition obligations	(72,482)	(143,768)	(164,216)
Debt issuance costs	(4,614)	(946)	(2,630)
Shares repurchased for payment of employee taxes on stock awards	(14,277)	(11,656)	(30,234)
Excess tax adjustment from share-based payment arrangements	3,579	3,323	17,999
Common stock issued under option and stock purchase programs	1,255	3,705	1,210
Payment of dividends	(20,026)	(18,219)	(13,484)
Other loan proceeds, net	940	13,282	0
Noncontrolling interest distribution, net	(1,054)	0	0
Net cash (used in) provided by financing activities	(128,388)	(208,741)	110,535
Net increase (decrease) in cash and cash equivalents	567	(32,295)	(67,443)
Cash and cash equivalents, beginning of period	152,159	184,454	251,897
Cash and cash equivalents, end of period	152,726	152,159	184,454
Cash paid during the period for:
Interest	22,850	15,480	9,940
Income taxes, net of refunds	84,951	75,930	65,588
Non-cash investing activities
Business acquisitions, contingent consideration	9,215	7,373	6,598
Non-cash financing activities:
Deferred business acquisition obligations	$ 13,195	$ 36,281	$ 149,521