Long-Term Debt - 2013 Senior Credit Facility (Details)		1 Months Ended		3 Months Ended		12 Months Ended
	Nov. 15, 2013 USD ($)	Dec. 31, 2015 USD ($)	Nov. 30, 2014 USD ($)	Jun. 30, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	May 06, 2016 USD ($)	Apr. 21, 2016 USD ($)
Debt And Credit Facility [Line Items]
Cash						$ 506,000
Repurchase amount				$ 71,152,000
Gain (loss) on extinguishment of debt				$ 38,497,000	$ 17,911,000	37,893,000	$ 17,911,000	$ (493,000)
Write-off of unamortized debt issuance cost						3,005,000
Gain on extinguishment of debt, tax effect						13,451,000
Provision (benefit) for corporate income taxes						9,771,000	(14,351,000)	52,611,000
Line of Credit [Member] | 2013 Senior Credit Facility [Member]
Debt And Credit Facility [Line Items]
Line of credit maximum borrowing capacity	$ 370,000,000
Covenant compliance, maximum percentage available on line of credit due to exceeded maximum leverage ratio	25.00%
Threshold from sale of assets used towards mandatory prepayments	$ 30,000,000
Proceeds from sale of assets						$ 43,500,000
Line of Credit [Member] | 2013 Senior Credit Facility [Member] | Leverage Ratio, Greater Than 2.50 [Member]
Debt And Credit Facility [Line Items]
Covenant compliance, maximum leverage ratio						2.50
Excess cash flow repayment percentage						50.00%
Line of Credit [Member] | 2013 Senior Credit Facility [Member] | Leverage Ratio, Greater than 2.00 but Less than 2.50 [Member]
Debt And Credit Facility [Line Items]
Covenant compliance, maximum leverage ratio						2.00
Excess cash flow repayment percentage						25.00%
Line of Credit [Member] | 2013 Senior Credit Facility [Member] | Leverage Ratio, Less Than or Equal to 2.00 [Member]
Debt And Credit Facility [Line Items]
Excess cash flow repayment percentage						0.00%
Line of Credit [Member] | 2013 Senior Credit Facility [Member] | Base Rate [Member]
Debt And Credit Facility [Line Items]
Debt basis spread on variable rate (as percent)	2.50%
Line of Credit [Member] | 2013 Senior Credit Facility [Member] | LIBOR [Member]
Debt And Credit Facility [Line Items]
Debt basis spread on variable rate (as percent)	3.50%
Secured Debt [Member] | 2013 Senior Credit Facility [Member]
Debt And Credit Facility [Line Items]
Debt unamortized discount	$ 4,356,000
Deferred debt issuance costs	5,119,000
Secured Debt [Member] | 2013 Term Loan Facility Maturing November 15, 2020 [Member]
Debt And Credit Facility [Line Items]
Long-term debt, gross	325,000,000	$ 275,417,000			275,417,000	$ 202,000,000	275,417,000
Proceeds from issuance of secured debt	$ 323,375,000
Debt instrument, discount percentage	0.50%
Debt unamortized discount	$ 1,625,000	6,418,000			6,418,000	$ 3,851,000	6,418,000
Percent of amendment fee paid to consenting lenders						0.25%
Repayment of term loan						$ 22,019,000
Gain (loss) on extinguishment of debt								(493,000)
Write-off of unamortized debt issuance cost								119,000
Debt mandatory prepayment from sale of assets			$ 13,500,000
Write-off of unamortized original issue discount								$ 374,000
Debt instrument, term after which excess cash flow is paid						95 days
Long-term debt						$ 196,825,000
Unamortized debt issuance costs						1,324,000
Secured Debt [Member] | 2013 Term Loan Facility Maturing November 15, 2020 [Member] | Base Rate [Member]
Debt And Credit Facility [Line Items]
Debt instrument, variable rate floor (as a percentage)	2.00%
Secured Debt [Member] | 2013 Term Loan Facility Maturing November 15, 2020 [Member] | LIBOR [Member]
Debt And Credit Facility [Line Items]
Debt instrument, variable rate floor (as a percentage)	1.00%
Revolving Credit Facility [Member] | 2013 Senior Credit Facility [Member]
Debt And Credit Facility [Line Items]
Repurchased face amount		29,829,000			29,829,000		29,829,000		$ 62,447,000	$ 8,705,000
Repurchase amount		$ 10,947,000			$ 10,947,000		$ 10,947,000		$ 25,978,000	$ 3,787,000
Repurchase amount, percentage of face value		36.70%			36.70%		36.70%		41.60%	43.50%
Write-off of unamortized debt issuance cost		$ 249,000				545,000
Write-off of debt discount		$ 707,000				$ 1,561,000
Revolving Credit Facility [Member] | 2013 Revolving Loan Facility Maturing November 15, 2018 [Member]
Debt And Credit Facility [Line Items]
Line of credit maximum borrowing capacity	$ 45,000,000
Covenant compliance, maximum percentage available on line of credit due to exceeded maximum leverage ratio						25.00%
Covenant compliance, maximum leverage ratio						4.50
Unused borrowing capacity based on leverage ratio						$ 11,250,000
Unused borrowing capacity						42,149,000
Letter of Credit [Member] | 2013 Senior Credit Facility [Member]
Debt And Credit Facility [Line Items]
Line of credit maximum borrowing capacity	$ 5,500,000
Letter of Credit [Member] | 2013 Revolving Loan Facility Maturing November 15, 2018 [Member]
Debt And Credit Facility [Line Items]
Letters of credit outstanding						$ 2,851,000