Fair Value - Assets and Liabilities Measured at Fair Value and Related Hierarchy Levels (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Financial Assets:
Total investment securities	$ 30,902	$ 30,460
Level 1
Financial Assets:
Executive deferred compensation plan trust	8,799	7,965
Level 2 | Interest rate swaps
Financial Assets:
Derivative asset	0	2,395
Liabilities
Interest rate swaps	49,812	19,764
Money Market Funds | Level 1
Financial Assets:
Money market funds	431,314	223,217
Municipal bonds | Level 2
Financial Assets:
Total investment securities	228	302
Asset-backed securities | Level 2
Financial Assets:
Total investment securities	238	247
Mortgage-backed securities | Level 2
Financial Assets:
Total investment securities	171	174
Pooled investment fund measured at net asset value | Net Asset Value
Financial Assets:
Total investment securities	5,000	5,000
Fixed-income mutual fund | Level 1
Financial Assets:
Total investment securities	25,265	24,737
Prepaid expenses and other current assets
Financial Assets:
Executive deferred compensation plan trust	700	900
Prepaid expenses and other current assets | Interest rate swaps
Financial Assets:
Derivative asset		2,400
Other assets
Financial Assets:
Executive deferred compensation plan trust		7,000	$ 8,100
Other current liabilities | Interest rate swaps
Liabilities
Interest rate swaps	21,000	6,700
Other liabilities | Interest rate swaps
Liabilities
Interest rate swaps	$ 28,800	$ 13,100