CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 99,037	$ 106,763	$ 100,491
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	152,925	141,633	129,251
Amortization of above/below market leases	(254)	(580)	(598)
Amortization of deferred financing costs and hedge amortization	3,338	2,370	1,676
Share-based compensation	14,384	12,038	8,946
Bad debt expense	291	(229)	1,338
Changes in operating assets and liabilities:
Accounts receivable	(2,836)	10,923	(5,087)
Deferred rent receivable	4,827	(3,124)	(3,645)
Deferred leasing costs	(13,422)	(11,672)	(13,315)
Other assets	(8,132)	(4,079)	(10,924)
Accounts payable and accrued expenses	8,208	3,502	1,224
Unearned revenue, prepaid rent and other liabilities	(9,097)	(1,275)	(2,235)
Operating leases	2,316	2,491	2,234
Net cash provided by operating activities	251,585	258,761	209,356
CASH FLOWS FROM INVESTING ACTIVITIES
Tenant improvements	(4,014)	(5,247)	(7,850)
Real estate improvements	(342,187)	(239,715)	(153,956)
Business combinations and asset acquisitions	(26,060)	(10,681)	(12,158)
Net cash used in investing activities	(372,261)	(255,643)	(173,964)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from exercise of stock options	364	310	4,820
Proceeds from revolving credit facility	397,298	253,036	274,000
Payments on revolving credit facility	(546,299)	(211,036)	(298,500)
Proceeds from unsecured debt	500,000	150,000	275,000
Payments of loan fees and costs	(6,337)	(5,038)	(2,410)
Redemption of preferred stock			(115,000)
Dividends and distributions	(223,901)	(193,038)	(172,484)
Net cash provided by (used in) financing activities	121,125	(5,766)	(34,574)
Net change in cash and cash equivalents	449	(2,648)	818
Cash and cash equivalents, beginning of period	2,599	5,247	4,429
Cash and cash equivalents, end of period	3,048	2,599	5,247
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Cash paid for interest, net of capitalized amounts	31,123	32,579	22,252
Cash paid for operating lease liabilities	25,206	21,994	20,764
NON-CASH INVESTING AND FINANCING ACTIVITY
Construction costs payable capitalized to real estate	64,776	41,328	32,228
Accrual of dividends and distributions	62,332	55,679	48,976
NON-CASH OPERATING ACTIVITY
Lease liabilities arising from obtaining right-of-use assets	$ 1,040	$ 114,989	$ 8,330