Sale of Common Stock (Details) - USD ($)								1 Months Ended	3 Months Ended
	Mar. 15, 2021	Mar. 15, 2021	Mar. 05, 2021	Feb. 02, 2021	Aug. 24, 2020	Mar. 09, 2020	Mar. 03, 2020	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Subsidiary, Sale of Stock [Line Items]
Maximum offering from universal shelf registration				$ 500,000
Term Of Securities Offered Under Self Registration				3 years
Sale of common stock, net (in shares)		1,927,049
Proceeds from sale of common stock		$ 108,676,000							$ 108,676,000	$ 2,500,000
Issuance cost		$ 877,000
Value Of Securities Available For Issuance Under Self Registration									$ 384,377
Granted (in shares)										102,906,000
Exercise of stock options (shares)									233,000
Proceeds from exercise of stock options									$ 6,000
2009 Stock Option Plan
Subsidiary, Sale of Stock [Line Items]
Granted (in shares)								49,061	0
Exercise price (in dollars per share)							$ 45.98	$ 44.99
2020 Incentive Award Plan
Subsidiary, Sale of Stock [Line Items]
Granted (in shares)							52,000	53,149	0
Exercise price (in dollars per share)							$ 46.91	$ 45.90
Public Offering [Member]
Subsidiary, Sale of Stock [Line Items]
Sale of common stock, net (in shares)			1,750,000
Share price			$ 56.85
Over-Allotment Option [Member]
Subsidiary, Sale of Stock [Line Items]
Sale of common stock, net (in shares)	177,049
Private Placement | 2009 Stock Option Plan
Subsidiary, Sale of Stock [Line Items]
Granted (in shares)							48,000
Securities Purchase Agreement
Subsidiary, Sale of Stock [Line Items]
Sale of common stock, net (in shares)					504,590
Share price					$ 50.00	$ 46.91
Issuance cost					$ 449,000
Additional shares of common stock					504,590
Exercise of stock options (shares)						53,293
Proceeds from exercise of stock options						$ 2,500,000