Basis of Presentation New Accounting Pronouncements (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Mar. 31, 2018	Apr. 01, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cash and Cash Equivalents, at Carrying Value	$ 177,487	$ 129,509	$ 186,766
Restricted cash	12,918	13,323	11,228
Restricted cash, Noncurrent	1,066	725	1,264
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	191,471	143,557	$ 199,258	$ 144,839
Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	6,500	$ 5,100
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets	454
Accounting Standards Update 2016-01 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets	1,621
Nonoperating Income (Expense) [Member] | Accounting Standards Update 2016-01 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	$ 1,600