Description of Business and Summary of Significant Accounting Policies Impact of Change in Accounting Policy (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Impact of adopting Topic 606 on the Company’s unaudited consolidated financial statements [Abstract]
Other current assets	$ 60,838	$ 59,274
Assets, Current	352,547	427,380
Deferred tax asset, net	58,686	54,629
Other assets	31,583	26,714
Assets	1,580,992	1,610,947
Deferred Revenue, Current	33,173	35,609
Liabilities, Current	242,154	317,428
Deferred Revenue, Noncurrent	8,649	9,051
Liabilities	1,011,944	1,066,510
Retained Earnings (Accumulated Deficit)	$ 556,364	$ 535,118