Revenue Recognition (Revenue Reconciliation) (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total revenues	$ 253,980	$ 256,573
Cost of sales	113,357	113,097
Total operating expenses	68,136	64,521
Provision for income taxes	11,994	18,929
Net income	34,466	$ 33,759
Impact of Change | New Revenue Standard Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total revenues	(5,945)
Cost of sales	(2,192)
Total operating expenses	(139)
Provision for income taxes	(981)
Net income	(2,633)
Without Adoption of ASC 606
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total revenues	248,035
Cost of sales	111,165
Total operating expenses	67,997
Provision for income taxes	11,013
Net income	$ 31,833