Summary of Significant Accounting Principles - Share Based Compensation and Other (Details) - USD ($)	3 Months Ended	12 Months Ended
Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Income Tax Examination, Penalties and Interest Accrued
Uncertain income tax positions	$ 0		$ 0
Accrual for interest or penalties	0		$ 0
Numerator:
Net income	62,660,000	$ 45,556,000
Less: earnings attributable to unvested restricted shares	(96,000)	(83,000)
Net income used in basic and diluted income per share	$ 62,564,000	$ 45,473,000
Denominator:
Weighted average common shares outstanding	243,637,891	222,498,630
Less: Weighted average number of shares of unvested restricted stock (in shares)	(282,405)	(313,876)
Weighted average shares outstanding used in basic income per share (in shares)	243,355,486	222,184,754
Effects of dilutive securities:
Add: Treasury stock method impact of potentially dilutive securities (in shares)		452,547
Weighted average shares outstanding used in diluted income per share (in shares)	243,355,486	222,637,301
Antidilutive unvested restricted shares (in shares)	85,405	125,317
Restricted Stock
Sharebased Compensation
Granted in period (in shares)	95,967
Vested in period (in shares)	105,544
Forfeited in period (in shares)	(763)
Shares repurchased in connection with tax withholding obligations (in shares)	37,410
Outstanding (in shares)	274,898
Restricted Stock Units
Sharebased Compensation
Vested in period (in shares)			247,553
Shares repurchased in connection with tax withholding obligations (in shares)	97,570
Restricted Stock Units \| Executive Officer \| Vesting Based On Service And Market Conditions
Sharebased Compensation
Granted in period (in shares)	534,141
Outstanding (in shares)	1,737,159

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