Stock-based Compensation - Trust Restricted Share Activity (Details) - $ / shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Weighted Average Grant Date Fair Value
Common stock, shares issued (in shares)	224,678,116	209,550,592
2013 Plan | Executive Awards
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Non-vested at the beginning of the period (in shares)	964,139	654,752	533,155
Granted (in shares)	265,275	482,646	229,884
Vested (in shares)	(252,844)	(173,259)	(104,553)
Forfeited (in shares)			(3,734)
Non-vested at the end of the period (in shares)	976,570	964,139	654,752
Weighted Average Grant Date Fair Value
Non-vested at beginning of period (in dollars per share)	$ 21.17	$ 22.99	$ 22.66
Granted (in dollars per share)	22.00	21.64	25.27
Vested (in dollars per share)	16.58	29.34	26.33
Forfeited (in dollars per share)			23.08
Non-vested at end of period (in dollars per share)	$ 22.59	$ 21.17	$ 22.99
Common stock, shares issued (in shares)	399,165	147,765	87,805
Restricted stock, shares issued net of shares for tax withholdings (in shares)	162,173	65,513	35,265
2013 Plan | Trustee Awards
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Non-vested at the beginning of the period (in shares)	59,820	67,297	67,158
Granted (in shares)	56,925	38,858	41,925
Vested (in shares)	(53,737)	(46,335)	(41,786)
Forfeited (in shares)			0
Non-vested at the end of the period (in shares)	63,008	59,820	67,297
Weighted Average Grant Date Fair Value
Non-vested at beginning of period (in dollars per share)	$ 18.81	$ 16.72	$ 16.01
Granted (in dollars per share)	17.35	19.30	17.89
Vested (in dollars per share)	18.38	16.19	16.75
Forfeited (in dollars per share)			0
Non-vested at end of period (in dollars per share)	$ 17.85	$ 18.81	$ 16.72