Condensed Consolidated Statement of Stockholders' Equity (Unaudited) (USD $) In Thousands, except Share data, unless otherwise specified	Common Stock [Member] Common Class A [Member] 2007 Incentive Plan [Member] 401(k) Plan [Member]	Common Stock [Member] Common Class A [Member] USD ($)	Common Stock [Member] 2007 Incentive Plan [Member] 401(k) Plan [Member]	Common Stock [Member] 401(k) Plan [Member] USD ($)	Common Stock [Member] USD ($)	Retained Earnings [Member] USD ($)	Treasury Stock [Member] Common Class A [Member] 2007 Incentive Plan [Member] 401(k) Plan [Member] USD ($)	Treasury Stock [Member] Common Class A [Member] USD ($)	Treasury Stock [Member] 2007 Incentive Plan [Member] 401(k) Plan [Member] USD ($)	Treasury Stock [Member] USD ($)	AOCI Attributable to Parent [Member] USD ($)	Common Class A [Member] USD ($)	2007 Incentive Plan [Member] 401(k) Plan [Member] USD ($)	401(k) Plan [Member] USD ($)	Total USD ($)
Balance at December 31, 2014 at Dec. 31, 2014		$ 17,096			$ 486,317	$ (202,939)		$ (22,398)		$ (41,072)	$ (20,812)	$ 216,192			$ 216,192
Balance at December 31, 2014 (in Shares) at Dec. 31, 2014		7,567,868			57,326,180			(1,578,554)		(4,814,716)
Net income						5,595									5,595
Issuance of common stock:
Underwritten public offering					167,528										167,528
Underwritten public offering (in Shares)					13,511,040
Issuance of common stock, Employee Benefit Plan				6			(287)		(818)				(1,105)	6
Issuance of common stock, Employee Benefit Plan (in Shares)	287,513		150,308	562			(32,817)		(67,989)
Share-based compensation		486			507										993
Balance at March 31, 2015 at Mar. 31, 2015		$ 17,582			$ 654,358	$ (197,344)		$ (22,685)		$ (41,890)	$ (20,812)	$ 389,209			$ 389,209
Balance at March 31, 2015 (in Shares) at Mar. 31, 2015		7,855,381			70,988,090			(1,611,371)		(4,882,705)