Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Taxes [Line Items]
Net deferred tax assets, noncurrent assets	$ 104,130,000	$ 93,565,000
Deferred income tax assets for state income tax NOLs	60,000,000	68,800,000	$ 56,700,000
Valuation allowance	46,676,000	50,969,000	49,500,000
Deferred tax assets for federal NOLs	119,100,000	51,400,000	25,500,000
Deferred income tax assets for federal income tax NOLs, valuation allowance	$ 0	0	$ 200,000
Federal NOLs, expiration year	2035
Excess tax benefits related to stock compensation		2,200,000
Accrued interest related to uncertain tax provisions	$ 2,700,000
Minimum
Income Taxes [Line Items]
Statutes of limitations for tax returns in state jurisdictions	3 years
Maximum
Income Taxes [Line Items]
Statutes of limitations for tax returns in state jurisdictions	5 years
State portion of deferred income tax valuation allowance
Income Taxes [Line Items]
Valuation allowance	$ 46,700,000	$ 50,900,000