Income Taxes - Deferred Income Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Other Comprehensive Income (Loss), Tax	$ (900)	$ (2,600)	$ (1,100)
Deferred Income Taxes [Abstract]
Deferred tax assets - current	10,566	8,225
Deferred tax assets - noncurrent	6,719	6,605
Deferred tax liabilities - current	(441)	(218)
Deferred tax liabilities - noncurrent	(5,187)	(9,576)
Net deferred tax assets	11,657	5,036
Valuation allowance	3,562	4,350
Deferred tax assets:
Accrued liabilities and reserves	16,498	14,941
Tax credit and loss carryforwards	5,126	7,437
Unrealized investment	558	2,219
Stock compensation	3,708	3,278
Other assets	5,263	4,775
Gross deferred tax assets	31,153	32,650
Valuation allowance	3,562	4,350
Net deferred tax assets	27,591	28,300
Deferred tax liabilities:
Fixed assets and intangibles	(14,445)	(18,004)
Revenue recognition	(312)	(2,800)
Other liabilities	(1,177)	(2,460)
Total deferred tax liabilities	$ (15,934)	$ (23,264)