Income Taxes - Income Tax Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Effective Income Tax Rate Reconciliation, Amount
Statutory rate		$ 25,209	$ 27,515	$ 49,805
State income tax, net of federal benefit		3,180	(1,207)	(4,784)
Nondeductible expenses		1,276	1,097	1,950
Acquisition of ABS		0	(10,189)	0
Equity based compensation		2,526	54	(12,718)
Deferred benefit on acquisitions		0	0	(6,201)
Foreign tax rate differential		1,964	3,557	(17,536)
Tax rate differences and credits	$ (90,800)	(1,867)	96,231	(91,109)
Uncertain tax positions		1,604	5,443	736
Foreign source dividends and deemed inclusions	$ 65,800	10,797	16,295	86,119
Valuation allowance		10,144	(85,876)	98,156
IRS audit adjustments		0	0	(699)
Termination of hedge accounting		4,533	0	0
U.S. Tax Reform		0	(62,836)	32,414
Disposition of subsidiary		(2,384)	0	0
Other		92	(142)	1,685
Income tax provision (benefit) for continuing operations		$ 57,074	$ (10,058)	$ 137,818
Effective Income Tax Rate Reconciliation, Percent
Statutory rate		21.00%	21.00%	35.00%
State income tax, net of federal benefit		2.60%	(0.90%)	(3.40%)
Nondeductible expenses		1.10%	0.80%	1.40%
Acquisition of ABS		0.00%	(7.80%)	0.00%
Equity based compensation		2.10%	0.00%	(8.90%)
Deferred benefit on acquisitions		0.00%	0.00%	(4.40%)
Foreign tax rate differential		1.60%	2.70%	(12.30%)
Tax rate differences and credits		(1.50%)	73.40%	(64.00%)
Uncertain tax positions		1.30%	4.20%	0.50%
Foreign source dividends and deemed inclusions		9.00%	12.40%	60.50%
Valuation allowance		8.40%	(65.50%)	69.00%
IRS audit adjustments		0.00%	0.00%	(0.50%)
Termination of hedge accounting		3.80%	0.00%	0.00%
U.S. Tax Reform		0.00%	(47.90%)	22.80%
Disposition of subsidiary		(2.00%)	0.00%	0.00%
Other		0.10%	(0.10%)	1.10%
Effective rate for continuing operations		47.50%	(7.70%)	96.80%