Summary of Stock Award Activity and Related Information (Details) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
		Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Outstanding Options, Shares Available for Grant [Roll Forward]
Shares Available for Grant, Balances (in shares)		2,511,625
Shares Available for Grant, Increase in available for grant associated with the merger (Note 3) (in shares)		228,452
Replacement stock options granted in connection with the merger (Note 3) (in shares)		(228,438)
Restricted stock units awarded (in shares)		(1,086,250)
Shares Available for Grant, Forfeited/cancelled (in shares)		94,411
Shares Available for Grant, Balances (in shares)		1,519,800	[1]	2,511,625
Outstanding Options, Shares [Roll Forward]
Replacement stock options granted in connection with the merger (Note 3) (in shares)		228,438
Outstanding Options at end of the period (in shares)		1,960,459
Non-vested Options, Shares [Roll Forward]
Stock options granted (in shares)		228,438
Restricted Stock Units, Unvested Shares [Roll Forward]
Restricted stock units award (in shares)		1,086,250
Stock Options [Member]
Outstanding Options, Shares Available for Grant [Roll Forward]
Replacement stock options granted in connection with the merger (Note 3) (in shares)		(228,438)		0		(200,000)
Outstanding Options, Shares [Roll Forward]
Outstanding Options at beginning of the period (in shares)		2,376,500
Replacement stock options granted in connection with the merger (Note 3) (in shares)		228,438		0		200,000
Options Exercised (in shares)		(621,506)
Options Forfeited/cancelled (in shares)		(22,973)
Outstanding Options at end of the period (in shares)		1,960,459	[1]	2,376,500
Outstanding Options Exercisable as of December 31, 2016 (in shares)		1,703,584
Outstanding Options Fully vested and expected to vest as of December 31, 2016 (in shares)		1,959,185
Outstanding Options, Weighted Average Exercise Price [Roll Forward]
Outstanding Options Weighted-Average Exercise Price, beginning of period (in dollars per share)		$ 21.56
Option Replacement stock options granted in connection with the merger (Note 3) Weighted-Average Exercise Price (in dollars per shares)		16.53
Options Exercised Weighted-Average Exercise Price (in dollars per share)		13.12
Options Forfeited/cancelled Weighted-Average Exercise Price (in dollars per share)		35.75
Outstanding Options Weighted-Average Exercise Price, end of period (in dollars per share)		23.48	[1]	$ 21.56
Outstanding Options Exercisable, Weighted-Average Exercise Price (in dollars per share)		20.02
Outstanding Options Fully vested and expected to vest Weighted-Average Exercise Price (in dollars per share)		$ 23.47
Outstanding Options Weighted-Average Remaining Contractual Term				5 years 21 days	[1]	5 years 4 months 17 days
Outstanding Options Exercisable, Weighted-Average Remaining Contractual Term				4 years 10 months 6 days
Outstanding Options Fully vested and expected to vest Weighted-Average Remaining Contractual Term				5 years 21 days
Outstanding Options, Aggregate Intrinsic Value	[2]			$ 107,273	[1]	$ 99,197
Outstanding Options Exercisable, Aggregate Intrinsic Value	[2]			99,113
Outstanding Options Fully vested and expected to vest, Aggregate Intrinsic Value	[2]			$ 107,234
Non-vested Options, Shares [Roll Forward]
Non-vested Shares, beginning of the period (in shares)		498,750
Stock options granted (in shares)		228,438		0		200,000
Non-vested Shares, Vested (in shares)		(448,924)
Non-vested Shares, Forfeited/cancelled (in shares)		(21,389)
Non-vested Shares, end of the period (in shares)		256,875	[1]	498,750
Non-vested Shares, Weighted-Average Grant-Date Fair Value [Roll Forward]
Non-vested shares, Weighted Average Grant-Date Fair Value, beginning of the period (in dollars per share)		$ 31.79
Non-vested shares, Replacement stock options granted in connection with the merger (Note 3), Weighted Average Grant-Date Fair Value (in dollars per shares)		46.85				$ 31.45
Non-vested shares Vested, Weighted Average Grant-Date Fair Value (in dollars per share)		39.17
Non-vested shares Forfeited/cancelled, Weighted Average Grant-Date Fair Value (in dollars per share)		38.28
Non-vested shares, Weighted Average Grant-Date Fair Value, end of the period (in dollars per share)		$ 31.75	[1]	$ 31.79
Restricted stock units [Member]
Outstanding Options, Shares Available for Grant [Roll Forward]
Restricted stock units awarded (in shares)		(1,086,250)		(33,750)		(210,000)
Restricted Stock Units, Unvested Shares [Roll Forward]
Restricted Stock Units Unvested Shares, beginning of the period (in shares)		188,000
Restricted stock units award (in shares)		1,086,250		33,750		210,000
Restricted Stock Units Unvested Shares, Vested (in shares)		(62,687)
Restricted Stock Units Unvested Shares, Forfeited/cancelled (in shares)		(71,438)
Restricted Stock Units Unvested Shares, end of the period (in shares)		1,140,125	[1]	188,000
Restricted Stock Units, Weighted-Average Grant-Date Fair Value [Roll Forward]
Restricted Stock Units, Weighted Average Grant-Date Fair Value, beginning of the period (in dollars per share)		$ 46.33
Restricted Stock Units, Awarded, Weighted Average Grant-Date Fair Value (in dollars per share)		63.99
Restricted Stock Units, Vested, Weighted Average Grant-Date Fair Value (in dollars per share)		46.14
Restricted Stock Units, Forfeited/cancelled, Weighted Average Grant-Date Fair Value (in dollars per share)		60.96
Restricted Stock Units, Weighted Average Grant-Date Fair Value, end of the period (in dollars per share)		$ 62.25	[1]	$ 46.33

[1] Includes 1,454,938 shares and 56,875 shares available for future grants under the 2015 Plan and the 2012 Plan, respectively. Additionally, 7,987 shares associated with the merger replacement stock options were unused.

[2] Aggregate intrinsic value represents the difference between the closing market price of Nexstar’s common stock on the last day of the fiscal period, which was $78.20 on December 31, 2017, and the stock option exercise prices multiplied by the number of options outstanding.