Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2017

Fair Value Disclosures [Abstract]

Components of Long-Term Debt and Methods Used in Estimating Fair Values

The following table summarizes components of the Company’s long-term debt and methods used in estimating their fair values:

	Maturity Date	Valuation Methodology
8% Senior Notes	*	Closing price listed on the New York Stock Exchange
3.875% Convertible Senior Notes	2019	Quoted price at January 3, 2018; Discounted cash flow method/Level 3 inputs at December 31, 2016
4.25% Convertible Senior Notes	2037	Quoted price
3.95% Promissory Note	2020	Discounted cash flow method/Level 3 inputs
4% Promissory Note	2031	Discounted cash flow method/Level 3 inputs
3.75% Promissory Note	2036	Discounted cash flow method/Level 3 inputs

* Redeemed on April 3, 2017.

Assets Measured at Estimated Fair Value on a Recurring Basis

The following tables present information about the Company’s financial assets measured at estimated fair value on a recurring basis. The table indicates the fair value hierarchy of the valuation techniques utilized by the Company to determine such fair value as of December 31, 2017 and 2016:

	Fair Value Measurements Using
	(Level 1)		(Level 2)		(Level 3)		Total
As of December 31, 2017
Financial Assets:
Cash and cash equivalents	$	255,884	$	—	$	—	$	255,884
Fixed-maturity securities:
U.S. Treasury and U.S. government agencies		40,527		1,500		—		42,027
Corporate bonds		106,109		994		—		107,103
State, municipalities, and political subdivisions		—		80,695		—		80,695
Exchange-traded debt		7,659		—		—		7,659
Total fixed-maturity securities		154,295		83,189		—		237,484
Equity securities		58,911		—		—		58,911
Total available-for-sale securities		213,206		83,189		—		296,395
Trading equity securities		1,045		—		—		1,045
Total	$	470,135	$	83,189	$	—	$	553,324

	Fair Value Measurements Using
	(Level 1)		(Level 2)		(Level 3)		Total
As of December 31, 2016
Financial Assets:
Cash and cash equivalents	$	280,531	$	—	$	—	$	280,531
Fixed-maturity securities:
U.S. Treasury and U.S. government agencies		1,939		—		—		1,939
Corporate bonds		73,519		985		—		74,504
State, municipalities, and political subdivisions		—		78,306		—		78,306
Exchange-traded debt		11,262		—		—		11,262
Redeemable preferred stock		237		—		—		237
Total fixed-maturity securities		86,957		79,291		—		166,248
Equity securities		53,035		—		—		53,035
Total available-for-sale securities		139,992		79,291		—		219,283
Total	$	420,523	$	79,291	$	—	$	499,814

Schedule of Fair Value Information for Financial Assets and Liabilities Carried on Balance Sheet

The following tables present fair value information for assets and liabilities that are carried on the balance sheet at amounts other than fair value as of December 31, 2017 and 2016:

	Carrying		Fair Value Measurements Using						Estimated
	Value		(Level 1)		(Level 2)		(Level 3)		Fair Value
As of December 31, 2017
Financial Assets:
Limited partnership investments	$	23,184	$	—	$	—	$	23,184	$	23,184
Financial Liabilities:
Long-term debt:
3.875% Convertible senior notes	$	85,436	$	—	$	90,827	$	—	$	90,827
4.25% Convertible senior notes		126,454		—		124,444		—		124,444
3.95% Promissory note		9,270		—		—		7,894		7,894
4% Promissory note		8,206		—		—		7,820		7,820
3.75% Promissory note		8,469		—		—		9,227		9,227
Total long-term debt	$	237,835	$	—	$	215,271	$	24,941	$	240,212

	Carrying		Fair Value Measurements Using						Estimated
	Value		(Level 1)		(Level 2)		(Level 3)		Fair Value
As of December 31, 2016
Financial Assets:
Limited partnership investments	$	29,263	$	—	$	—	$	29,263	$	29,263
Financial Liabilities:
Revolving credit facility	$	9,463	$	—	$	—	$	9,463	$	9,463
Long-term debt:
8% Senior notes	$	39,448	$	—	$	41,618	$	—	$	41,618
3.875% Convertible senior notes		81,988		—		—		84,696		84,696
4% Promissory note		8,660		—		—		8,664		8,664
3.75% Promissory note		8,767		—		—		8,506		8,506
Total long-term debt	$	138,863	$	—	$	41,618	$	101,866	$	143,484