Income Taxes - Tax Effects of Cumulative Temporary Differences (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred income tax assets:
Accrued expenses	$ 1,588	$ 1,126
Allowance accounts	6,161	6,415
Net operating loss carryforward	105,844	96,854
Equity method investment	35,292	35,292
Original issue discount	6,000	8,073
Interest limitation	10,132	5,845
Basis in identified intangibles	7,090	4,146
Tax credit carryforwards	5,070	5,345
Other	4,443	4,600
Total deferred income tax asset	181,620	167,696
Valuation allowance	(170,937)	(160,505)
Net deferred income tax asset	10,683	7,191
Deferred income tax liabilities:
Unbilled receivables	(1,949)	0
Total deferred income tax asset, net	$ 8,734	$ 7,191