Related Party Transactions (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($) ft² Director shares	Dec. 31, 2014 USD ($) shares
Related Party Transaction [Line Items]
Number of board of directors | Director	2
Rental expense for operating leases	$ 1,261	$ 1,229
Payment of dividends on Series D Preferred Stock	399	471
Redemption of Series D preferred stock	0	1,000
Series D Preferred Stock [Member]
Related Party Transaction [Line Items]
Payment of dividends on Series D Preferred Stock	$ 399	471
Redemption of Series D preferred stock		1,000
Affiliated Entity [Member]
Related Party Transaction [Line Items]
Office and covered garage space leased (in square feet) | ft²	49,586
Rental expense for operating leases	$ 875	852
Members of Management [Member]
Related Party Transaction [Line Items]
Aggregate carrying value of investments in Gray	$ 14,043	$ 9,242
Members of Management [Member] | Class A common stock [Member]
Related Party Transaction [Line Items]
Shares of Gray common stock owned (in shares) | shares	880,272	880,272
Members of Management [Member] | Common Stock [Member]
Related Party Transaction [Line Items]
Shares of Gray common stock owned (in shares) | shares	106,000	106,000