Income Taxes Narrative (Details) - USD ($)	9 Months Ended		12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Mar. 31, 2018	Mar. 31, 2017
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Transition tax due to repatriation of foreign earnings	$ 8,802,000			$ 52,800,000
Transition tax related to repatriation of foreign earnings payable in next twelve months	756,000			$ 4,557,000
Change in deferred tax assets valuation allowance	13,400,000
Unrecognized tax benefits and associated interest and penalties	10,250,000
Unrecognized tax benefits period increase (decrease)	(3,720,000)	$ 0
Unrecognized tax benefits, decrease resulting from settlements	4,437,000
Gross increase related to current year tax positions	717,000
Scenario, Forecast
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Federal statutory income tax rate			31.50%
Noncurrent Income Tax Liability
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Unrecognized tax benefits and associated interest and penalties	7,958,000
Current Income Tax Liability
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Unrecognized tax benefits and associated interest and penalties	$ 2,292,000