Parent Company - Condensed Statements of Comprehensive Income (Details) - USD ($) $ in Thousands	4 Months Ended	9 Months Ended	12 Months Ended
	Apr. 15, 2015	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues:
Total revenue			$ 1,027,982	$ 702,272	$ 796,213
Expenses
Operations and administrative			65,137	23,039	25,991
Net income (loss)	$ 83,147	$ 114,343	18,898	158,340	197,490
Net income attributable to common stockholders			2,939	32,980	20,887
Foreign currency translation adjustment, net of taxes	$ (4,633)	$ 378	9,117	(1,165)	(4,255)
Comprehensive income (loss) attributable to common stockholders			6,182	32,629	20,986
VFH
Revenues:
Service fee revenue					445
Other Income			86,599
Total revenue			86,599		445
Expenses
Operations and administrative			181	198	447
Income (loss) before equity in income of subsidiary			86,418	(198)	(2)
Equity in income of subsidiary, net of tax			(83,479)	33,178	104,036
Net income (loss)			2,939	32,980	104,034
Net income attributable to common stockholders			2,939	32,980	20,887
Foreign currency translation adjustment, net of taxes			3,243	(351)	(4,534)
Comprehensive income (loss) attributable to common stockholders			$ 6,182	$ 32,629	$ 16,353