Grants and other liabilities (Tables)

3 Months Ended

Mar. 31, 2019

Grants and other liabilities [Abstract]

Grants and other non-current liabilities

	Balance as of March 31,		Balance as of December 31,
	2019		2018
	($ in thousands)
Grants		1,134,944		1,150,805
Other Liabilities		518,379		507,321
Grant and other non-current liabilities		1,653,323		1,658,126