Investments in Available-for-Sale Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Successor [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost Basis	$ 89,910
Gross Unrealized Gains	388
Gross Unrealized Losses	(89)
Fair Value	90,209
Total Investments	88,072
Successor [Member] | Short-term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Corporate notes and bonds	88,072
Total Investments	88,072
Successor [Member] | Other Assets [Member]
Schedule of Available-for-sale Securities [Line Items]
Equity Securities, Fair Value	2,137
Successor [Member] | Corporate Notes and Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Debt Securities, Amortized Cost Basis	88,161
Debt Securities, Gross Unrealized Gains	0
Debt Securities, Gross Unrealized Losses	(89)
Debt Securities, Fair Value	88,072
Successor [Member] | Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Equity Securities, Amortized Cost Basis	1,749
Equity Securities, Gross Unrealized Gains	388
Equity Securities, Gross Unrealized Losses	0
Equity Securities, Fair Value	$ 2,137
Predecessor [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost Basis		$ 204,441
Gross Unrealized Gains		668
Gross Unrealized Losses		(3,199)
Fair Value		201,910
Total Investments		200,192
Predecessor [Member] | Short-term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
US government and agency securities		9,995
Corporate notes and bonds		190,197
Total Investments		200,192
Predecessor [Member] | Other Assets [Member]
Schedule of Available-for-sale Securities [Line Items]
Equity Securities, Fair Value		1,718
Predecessor [Member] | US Government and Agency Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Debt Securities, Amortized Cost Basis		10,007
Debt Securities, Gross Unrealized Gains		0
Debt Securities, Gross Unrealized Losses		(12)
Debt Securities, Fair Value		9,995
Predecessor [Member] | Corporate Notes and Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Debt Securities, Amortized Cost Basis		190,496
Debt Securities, Gross Unrealized Gains		0
Debt Securities, Gross Unrealized Losses		(299)
Debt Securities, Fair Value		190,197
Predecessor [Member] | Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Equity Securities, Amortized Cost Basis		3,938
Equity Securities, Gross Unrealized Gains		668
Equity Securities, Gross Unrealized Losses		(2,888)
Equity Securities, Fair Value		$ 1,718