Condensed Consolidated Statements of Cash Flows (unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash flow from operating activities
Net income (loss)	$ 1,231	$ (20,000)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	114,721	101,361
Amortization of deferred financing costs and debt discount	6,034	5,265
Deferred income taxes	(1,502)	(1,002)
Straight-line revenues	(4,592)	(3,629)
Stock-based compensation	2,210	1,632
Change in fair value of contingent consideration	(3,864)	10,910
Other	921	124
Changes in assets and liabilities, net of acquisitions:
Accounts receivable	6,409	1,014
Other assets	(4,621)	(1,626)
Accounts payable, accrued expenses and other liabilities	39,919	34,153
Net cash provided by operating activities	156,866	128,202
Cash flow from investing activities
Acquisition of businesses, net of cash acquired		248
Acquisition of ground lease investments		(7,191)
NMS asset acquisitions (Note 4)	(962)	(64,622)
Capital expenditures - other	(51,143)	(14,931)
Net cash used in investing activities	(52,105)	(86,496)
Cash flow from financing activities
Principal payments on debt	(5,270)	(5,270)
Dividends paid	(105,920)	(94,133)
Payments of contingent consideration	(12,662)	(18,791)
Distributions paid to noncontrolling interest	(2,479)
Borrowings under revolving credit facility	70,000	25,000
Payments under revolving credit facility	(50,000)	(25,000)
Capital lease payments	(899)	(672)
Deferred financing costs		(24,418)
Common stock issuance, net of costs		(54)
Net share settlement	(658)	(1,690)
Net cash used in financing activities	(107,888)	(145,028)
Effect of exchange rates on cash and cash equivalents	263	294
Net decrease in cash and cash equivalents	(2,864)	(103,028)
Cash and cash equivalents at beginning of period	59,765	171,754
Cash and cash equivalents at end of period	56,901	68,726
Non-cash investing and financing activities:
Property and equipment acquired but not yet paid	18,078	4,013
Tenant capital improvements	$ 47,352	$ 33,824