Fair Value of Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2016

Fair Value of Financial Instruments

Fair value measurements for available-for-sale investments

	As of December 31, 2016
	Total		Level 1 Inputs		Level 2 Inputs		Level 3 Inputs
U.S. Treasury securities	$	302	$	—	$	302	$	—
Obligations of states and political subdivisions		390,433		—		390,433		—
Residential mortgage-backed securities		252,631		—		252,631		—
Commercial mortgage-backed securities		35,454		—		35,454		—
Other asset-backed securities		70,410		—		70,410		—
Corporate and other securities		405,039		—		405,039		—
Equity securities		85,134		84,456		—		678
Total investment securities	$	1,239,403	$	84,456	$	1,154,269	$	678

	As of December 31, 2015
	Total		Level 1 Inputs		Level 2 Inputs		Level 3 Inputs
U.S. Treasury securities	$	1,801	$	—	$	1,801	$	—
Obligations of states and political subdivisions		397,922		—		397,922		—
Residential mortgage-backed securities		241,456		—		241,456		—
Commercial mortgage-backed securities		28,663		—		28,663		—
Other asset-backed securities		23,931		—		23,931		—
Corporate and other securities		387,864		—		387,864		—
Equity securities		91,107		90,560		—		547
Total investment securities	$	1,172,744	$	90,560	$	1,081,637	$	547

Changes in the Company's Level 3 fair value securities

	Year Ended December 31,
	2016		2015		2014
Balance at beginning of period	$	547	$	505	$	—
Net gains and losses included in earnings		—		—		—
Net gains included in other comprehensive income		—		—		—
Purchases		131		42		505
Sales		—		—		—
Transfers into Level 3		—		—		—
Transfers out of Level 3		—		—		—
Balance at end of period	$	678	$	547	$	505