Condensed Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 22,846	$ 19,604
Adjustments to reconcile net income to net cash provided by operating activities -
Depreciation and amortization	15,053	14,779
Amortization of debt issuance costs and premium	1,022	880
Amortization of unearned income and initial direct costs on direct financing leases	(4,083)	(4,241)
Payments received under direct financing leases	5,315	5,462
Equity in earnings of investments in equity investees	(3,936)	(3,492)
Cash distributions of earnings of equity investees	6,047	5,911
Non-cash effect of equity-based compensation plans	7,021	123
Deferred and other tax liabilities	(323)	(37)
Unrealized gains on derivative transactions	(52)	(1,992)
Other, net	71	193
Net changes in components of operating assets and liabilities, (See Note 10)	(10,165)	(17,268)
Net cash provided by operating activities	38,816	19,922
CASH FLOWS FROM INVESTING ACTIVITIES:
Payments to acquire fixed and intangible assets	(47,151)	(47,473)
Cash distributions received from equity investees - return of investment	3,583	4,314
Investments in equity investees	(64,534)	(33,542)
Acquisitions	0	(205,576)
Proceeds from asset sales	332	359
Other, net	755	(97)
Net cash used in investing activities	(107,015)	(282,015)
CASH FLOWS FROM FINANCING ACTIVITIES:
Borrowings on senior secured credit facility	386,400	509,200
Repayments on senior secured credit facility	(615,400)	(480,300)
Proceeds from issuance of senior unsecured notes, including premium	350,000	101,000
Debt issuance costs	(8,157)	(2,584)
Issuance of common units for cash, net	0	169,524
Distributions to common unitholders	(39,390)	(31,677)
Other, net	(553)	437
Net cash provided by financing activities	72,900	265,600
Net increase in cash and cash equivalents	4,701	3,507
Cash and cash equivalents at beginning of period	11,282	10,817
Cash and cash equivalents at end of period	$ 15,983	$ 14,324