Income Taxes (Components of Provision for Income Taxes) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2018
Current
Federal									$ 24,051	$ 27,629	$ 31,327
State									2,506	3,156	2,686
Foreign									8,473	7,193	5,588
Deferred
Federal									14,119	(35,760)	(270,796)
State									(341)	(4,101)	(1,240)
Foreign									62	(372)	(49)
Total provision (benefit) for income taxes	$ 13,489	$ 12,496	$ 10,760	$ 12,125	$ (39,756)	$ 12,829	$ 12,678	$ 11,994	$ 48,870	$ (2,255)	$ (232,484)