Condensed Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 68,222	$ 69,382
Adjustments to reconcile net income to net cash provided by operating activities -
Depreciation and amortization	46,789	45,447
Amortization of debt issuance costs and premium	3,234	2,655
Amortization of unearned income and initial direct costs on direct financing leases	(12,160)	(12,641)
Payments received under direct financing leases	15,946	16,389
Equity in earnings of investments in equity investees	(16,618)	(7,971)
Cash distributions of earnings of equity investees	24,352	16,151
Non-cash effect of equity-based compensation plans	10,579	4,617
Deferred and other tax liabilities	(186)	(9,156)
Unrealized gains on derivative transactions	(2,802)	(1,251)
Other, net	336	438
Net changes in components of operating assets and liabilities, (Note 11)	(28,354)	18,878
Net cash provided by operating activities	109,338	142,938
CASH FLOWS FROM INVESTING ACTIVITIES:
Payments to acquire fixed and intangible assets	(199,634)	(116,702)
Cash distributions received from equity investees - return of investment	8,272	10,918
Investments in equity investees	(71,443)	(57,072)
Acquisitions	(230,921)	(205,576)
Proceeds from asset sales	810	667
Other, net	(1,004)	(1,012)
Net cash used in investing activities	(493,920)	(368,777)
CASH FLOWS FROM FINANCING ACTIVITIES:
Borrowings on senior secured credit facility	1,234,500	1,407,000
Repayments on senior secured credit facility	(1,323,200)	(1,333,300)
Proceeds from issuance of senior unsecured notes, including premium	350,000	101,000
Debt issuance costs	(8,157)	(7,109)
Issuance of common units for cash, net	263,597	169,421
Distributions to common unitholders	(122,097)	(104,008)
Other, net	(4,484)	(2,521)
Net cash provided by financing activities	390,159	230,483
Net increase in cash and cash equivalents	5,577	4,644
Cash and cash equivalents at beginning of period	11,282	10,817
Cash and cash equivalents at end of period	$ 16,859	$ 15,461