Stockholders' Equity and Earnings Per Share (Textual) (Details)	12 Months Ended	49 Months Ended
	Dec. 31, 2018 USD ($) vote shares	Dec. 31, 2017 USD ($) shares	Feb. 14, 2018 USD ($)
2018 Stock Repurchase Program
Class of Stock [Line Items]
Authorized amount available for repurchase | $			$ 25,000,000
Treasury Stock, Value, Acquired, Par Value Method | $	$ 1,300,000
Class A Common Stock
Class of Stock [Line Items]
Votes per share | vote	1
Common stock, shares authorized | shares	25,000,000
Treasury stock (in shares) | shares	2,862,442	2,931,590
Class A Common Stock | 2016 Stock Repurchase Program
Class of Stock [Line Items]
Treasury stock, shares acquired (in shares) | shares		1,855,923
Treasury stock, value | $	$ 39,047
Treasury Stock, Value, Acquired, Par Value Method | $		$ 101,700,000
Class B Common Stock
Class of Stock [Line Items]
Votes per share | vote	10
Common stock, shares authorized | shares	6,756,176