Summary of Significant Accounting Policies - Consolidated VIEs (Details) - USD ($) $ in Thousands		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Variable Interest Entity [Line Items]
Spectrum asset		$ 305,764
Other current assets		71,859	$ 57,479
Total current assets		1,056,218	363,217
Liability to surrender spectrum asset		314,087
Other current liabilities		17,169	9,714
Total current liabilities		670,703	189,578
Current assets:
Cash and cash equivalents		115,652	87,680	$ 43,416	$ 131,912
Accounts receivable, net		562,943	218,058
Spectrum asset		305,764
Prepaid expenses and other current assets		71,859	30,760
Total current assets		1,056,218	363,217
Property and equipment, net		734,138	276,153
Goodwill		2,142,846	473,304	451,662
FCC licenses		1,767,638	542,524	$ 489,335
Other intangible assets, net		1,581,626	324,737
Other noncurrent assets, net		199,181	85,070
Total assets	[1]	7,481,647	2,966,085
Current liabilities:
Current portion of debt		92,808	28,093
Interest payable		39,563	44,190
Liability to surrender spectrum asset		314,087
Other current liabilities		17,169	9,714
Total current liabilities		670,703	189,578
Debt		4,269,652	2,314,326
Other noncurrent liabilities		340,541	45,819
Total liabilities	[1]	5,900,337	2,681,731
Consolidated VIEs [Member]
Variable Interest Entity [Line Items]
Consolidated VIEs, Assets		426,879	226,198
Spectrum asset		26,695
Total current assets		75,044	31,208
Consolidated VIEs, Liabilities		81,832	39,196
Liability to surrender spectrum asset		27,347
Other current liabilities		24,146	12,606
Total current liabilities		109,052	21,971
Current assets:
Cash and cash equivalents		17,180	7,302
Accounts receivable, net		24,407	20,553
Spectrum asset		26,695
Prepaid expenses and other current assets		6,762	3,353
Total current assets		75,044	31,208
Property and equipment, net		25,971	29,984
Goodwill		163,549	98,107
FCC licenses		151,808	114,791
Other intangible assets, net		97,757	87,668
Other noncurrent assets, net		9,443	13,233
Total assets		523,572	374,991
Current liabilities:
Current portion of debt		56,565	8,334
Interest payable		994	1,031
Liability to surrender spectrum asset		27,347
Other current liabilities		24,146	12,606
Total current liabilities		109,052	21,971
Debt		245,523	268,499
Other noncurrent liabilities		30,594	26,590
Total liabilities		385,169	317,060
Consolidated VIEs [Member] | Current assets [Member]
Variable Interest Entity [Line Items]
Spectrum asset		26,695
Other current assets		22,038	3,638
Total current assets		48,733	3,638
Current assets:
Spectrum asset		26,695
Total current assets		48,733	3,638
Consolidated VIEs [Member] | Property and equipment, net [Member]
Variable Interest Entity [Line Items]
Consolidated VIEs, Assets		7,517	6,944
Consolidated VIEs [Member] | Goodwill [Member]
Variable Interest Entity [Line Items]
Consolidated VIEs, Assets		130,362	46,465
Consolidated VIEs [Member] | FCC licenses [Member]
Variable Interest Entity [Line Items]
Consolidated VIEs, Assets		151,808	114,791
Consolidated VIEs [Member] | Other intangible assets, net [Member]
Variable Interest Entity [Line Items]
Consolidated VIEs, Assets		81,916	53,747
Consolidated VIEs [Member] | Other noncurrent assets, net [Member]
Variable Interest Entity [Line Items]
Consolidated VIEs, Assets		6,543	613
Consolidated VIEs [Member] | Current liabilities [Member]
Variable Interest Entity [Line Items]
Liability to surrender spectrum asset		27,347
Other current liabilities		24,146	12,606
Total current liabilities		51,493	12,606
Current liabilities:
Liability to surrender spectrum asset		27,347
Other current liabilities		24,146	12,606
Total current liabilities		51,493	12,606
Consolidated VIEs [Member] | Noncurrent liabilities [Member]
Variable Interest Entity [Line Items]
Consolidated VIEs, Liabilities		$ 30,339	$ 26,590

[1] The consolidated total assets as of December 31, 2017 and 2016 include certain assets held by consolidated VIEs of $426.9 million and $226.2 million, respectively, which are not available to be used to settle the obligations of Nexstar. The consolidated total liabilities as of December 31, 2017 and 2016 include certain liabilities of consolidated VIEs of $81.8 million and $39.2 million, respectively, for which the creditors of the VIEs have no recourse to the general credit of Nexstar. See Note 2 for additional information.