Stockholders' Equity (Details) - USD ($) $ in Thousands	3 Months Ended			12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Jun. 30, 2016	Dec. 31, 2018
Class of Stock [Line Items]
Stock Repurchased	3,600,000
Treasury Stock, Value, Acquired, Cost Method	$ 172,600
Stock Repurchased and Retired During Period, Value	$ 62,966	$ 1,177
Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation	80,516
IGC [Member]
Class of Stock [Line Items]
Stock Repurchased and Retired During Period, Shares			935,231
2012 Repurchase Program [Member]
Class of Stock [Line Items]
Maximum number of shares authorized to be repurchased	5,000,000
Stock Repurchased				600,000
Treasury Stock, Value, Acquired, Cost Method				$ 42,500
Stock Repurchased and Retired During Period, Shares	680,016
Stock Repurchased and Retired During Period, Value	$ 55,600
Stock Repurchase Program, Remaining Authorized Repurchase Amount	460,803