Condensed Consolidated Statement of Equity - USD ($) shares in Thousands, $ in Thousands	Total	Cumulative Effect, Period Of Adoption, Adjustment	Common Stock	Additional Paid-in Capital	Distributions in Excess of Accumulated Earnings	Distributions in Excess of Accumulated Earnings Cumulative Effect, Period Of Adoption, Adjustment	Accumulated Other Comprehensive Loss	Accumulated Other Comprehensive Loss Cumulative Effect, Period Of Adoption, Adjustment	Noncontrolling Interest	Noncontrolling Interest Cumulative Effect, Period Of Adoption, Adjustment
Issuance of common stock under:
Cumulative effect upon adoption of ASU No. 2016-13	$ 6,393,844	$ 181	$ 7	$ 7,093,079	$ (812,796)		$ (13,217)	$ 175	$ 126,771	$ 6
Balance at period beginning (in shares) at Dec. 31, 2018			65,890
Balance at period beginning at Dec. 31, 2018	6,393,844	181	$ 7	7,093,079	(812,796)		(13,217)	175	126,771	6
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	223,566				211,133				12,433
Reversal of unrealized gains upon the sale of marketable debt securities	(32)						(31)		(1)
Change in fair value of derivatives and amortization of swap settlements	(6,354)						(6,140)		(214)
Change in fair value of marketable debt securities, net	228						221		7
Issuance of common stock under:
Stock option and restricted stock plans, net (in shares)			62
Stock option and restricted stock plans, net	5,228			5,228
Sale of common stock, net	(82)			(82)
Equity based compensation costs	6,100			5,472					628
Retirement of common stock, net (in shares)			(234)
Retirement of common stock, net	(56,989)		$ 0	(56,989)
Cumulative effect upon adoption of ASU No. 2016-13	6,393,844	181	$ 7	7,031,886	(857,994)		(13,217)	$ 175	126,771	$ 6
Changes in the redemption value of redeemable noncontrolling interest	(1,428)			(2,739)					1,311
Changes in noncontrolling interest from acquisition	65,472								65,472
Distributions to noncontrolling interest	(14,108)								(14,108)
Redemptions of noncontrolling interest (in shares)			9
Redemptions	(14,179)			(12,083)					(2,096)
Common stock dividends	(256,331)				(256,331)
Balance at period end (in shares) at Jun. 30, 2019			65,727
Balance at period end at Jun. 30, 2019	6,345,116		$ 7	7,031,886	(857,994)		(18,992)		190,209
Issuance of common stock under:
Cumulative effect upon adoption of ASU No. 2016-13	6,317,195		$ 7	7,028,154	(822,087)		(14,817)		125,938
Balance at period beginning (in shares) at Mar. 31, 2019			65,716
Balance at period beginning at Mar. 31, 2019	6,317,195		$ 7	7,028,154	(822,087)		(14,817)		125,938
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	98,061				92,275				5,786
Reversal of unrealized gains upon the sale of marketable debt securities	(65)						(63)		(2)
Change in fair value of derivatives and amortization of swap settlements	(4,361)						(4,214)		(147)
Change in fair value of marketable debt securities, net	105						102		3
Issuance of common stock under:
Stock option and restricted stock plans, net (in shares)			11
Stock option and restricted stock plans, net	2,024			2,024
Sale of common stock, net	(62)			(62)
Equity based compensation costs	3,500			3,171					329
Cumulative effect upon adoption of ASU No. 2016-13	6,345,116		$ 7	7,031,886	(857,994)		(18,992)		190,209
Changes in the redemption value of redeemable noncontrolling interest	339			288					51
Changes in noncontrolling interest from acquisition	65,472								65,472
Distributions to noncontrolling interest	(6,944)								(6,944)
Redemptions	(1,966)			(1,689)					(277)
Common stock dividends	(128,182)				(128,182)
Balance at period end (in shares) at Jun. 30, 2019			65,727
Balance at period end at Jun. 30, 2019	6,345,116		$ 7	7,031,886	(857,994)		(18,992)		190,209
Issuance of common stock under:
Cumulative effect upon adoption of ASU No. 2016-13	6,345,116		7	7,031,886	(857,994)		(18,992)		190,209
Cumulative effect upon adoption of ASU No. 2016-13	6,403,504	(190)	$ 7	7,121,927	(887,619)	$ (190)	(13,888)		183,077
Balance at period beginning (in shares) at Dec. 31, 2019			66,092
Balance at period beginning at Dec. 31, 2019	6,403,504	(190)	$ 7	7,121,927	(887,619)	(190)	(13,888)		183,077
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	418,841				399,464				19,377
Cash flow hedge losses reclassified to earnings	3,282						3,171		111
Change in fair value of derivatives and amortization of swap settlements	(8,003)						(7,732)		(271)
Change in fair value of marketable debt securities, net	(270)						(261)		(9)
Issuance of common stock under:
Stock option and restricted stock plans, net (in shares)			95
Stock option and restricted stock plans, net	9,201			9,201
Sale of common stock, net	(133)			(133)
Equity based compensation costs	6,933			6,677					256
Retirement of common stock, net (in shares)			(864)
Retirement of common stock, net	(196,404)			(196,404)
Cumulative effect upon adoption of ASU No. 2016-13	6,352,881	$ (190)	$ 7	6,944,805	(760,028)	$ (190)	(13,888)		186,807
Changes in the redemption value of redeemable noncontrolling interest	4,169			4,542					(373)
Changes in noncontrolling interest from acquisition	1,349								1,349
Distributions to noncontrolling interest	(16,012)								(16,012)
Redemptions of noncontrolling interest (in shares)			8
Redemptions	(1,703)			(1,005)					(698)
Common stock dividends	(271,683)				(271,683)
Balance at period end (in shares) at Jun. 30, 2020			65,331
Balance at period end at Jun. 30, 2020	6,352,881		$ 7	6,944,805	(760,028)		(18,710)		186,807
Issuance of common stock under:
Cumulative effect upon adoption of ASU No. 2016-13	6,417,949		$ 7	6,959,523	(708,697)		(22,668)		189,784
Balance at period beginning (in shares) at Mar. 31, 2020			65,412
Balance at period beginning at Mar. 31, 2020	6,417,949		$ 7	6,959,523	(708,697)		(22,668)		189,784
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	90,076				84,458				5,618
Cash flow hedge losses reclassified to earnings	3,282						3,171		111
Change in fair value of derivatives and amortization of swap settlements	779						754		25
Change in fair value of marketable debt securities, net	35						33		2
Issuance of common stock under:
Stock option and restricted stock plans, net (in shares)			6
Stock option and restricted stock plans, net	536			536
Sale of common stock, net	(63)			(63)
Equity based compensation costs	5,235			5,058					177
Retirement of common stock, net (in shares)			(88)
Retirement of common stock, net	(20,093)		$ 0	(20,093)
Cumulative effect upon adoption of ASU No. 2016-13	6,352,881		$ 7	6,944,805	(760,028)		(18,710)		186,807
Changes in the redemption value of redeemable noncontrolling interest	(598)			(199)					(399)
Distributions to noncontrolling interest	(8,133)								(8,133)
Redemptions of noncontrolling interest (in shares)			1
Redemptions	(335)			43					(378)
Common stock dividends	(135,789)				(135,789)
Balance at period end (in shares) at Jun. 30, 2020			65,331
Balance at period end at Jun. 30, 2020	6,352,881		$ 7	6,944,805	(760,028)		(18,710)		186,807
Issuance of common stock under:
Cumulative effect upon adoption of ASU No. 2016-13	$ 6,352,881		$ 7	$ 6,944,805	$ (760,028)		$ (18,710)		$ 186,807