Stockholders' Equity (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Sep. 30, 2016	Jun. 30, 2020	Jun. 30, 2019
Class of Stock [Line Items]
Stock Repurchased				3,900,000
Treasury Stock, Value, Acquired, Cost Method				$ 196,200
Stock Repurchased and Retired During Period, Value	$ 25,503	$ 2,630		$ 88,469	$ 3,807
Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation	24,947
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			5,000,000
Stock Repurchased				600,000
Treasury Stock, Value, Acquired, Cost Method				$ 42,500
Stock Repurchased and Retired During Period, Shares				1,000,000
Stock Repurchased and Retired During Period, Value				$ 79,100
Stock Repurchase Program, Remaining Authorized Repurchase Amount	140,819			140,819