Stock-Based Compensation (Details 2) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended		1 Months Ended		6 Months Ended	1 Months Ended		6 Months Ended	1 Months Ended
	Jun. 30, 2013 Restricted stock units	Jun. 30, 2012 Restricted stock units	Jun. 30, 2013 Restricted stock units	Jun. 30, 2012 Restricted stock units	Nov. 30, 2008 Restricted stock units granted in 2008	Jul. 31, 2008 Restricted stock units granted in 2008	Jun. 30, 2013 Restricted stock units granted in 2008	Jun. 30, 2013 Restricted stock units granted in connection with the Central Merger	Oct. 31, 2012 Restricted stock units granted in connection with the Central Merger	Jun. 30, 2013 Restricted stock units granted in connection with the Central Merger	Oct. 31, 2012 Restricted stock units granted in connection with the Central Merger Employment agreement
Stock-Based Compensation
Restricted stock units awarded (in shares)					5,000	750,000		4,247	191,895		30,529
Vesting rights on each specified anniversary of the grant date (as a percent)							33.00%			33.00%
Number of years from grant date for first one-third vesting							10 years			1 year
Number of years from grant date for second one-third vesting							11 years			2 years
Number of years from grant date for third one-third vesting							12 years			3 years
Vesting period									3 years
Restricted stock units vested (in shares)	27,000	104,000	27,000	146,000
Restricted stock units forfeited (in shares)	0	0	0	0
Recognized stock-based compensation expense	$ 1,017	$ 257	$ 2,059	$ 618
Unrecognized stock-based compensation costs	$ 7,095		$ 7,095
Weighted average remaining recognition period of unrecognized stock-based compensation costs			3 years 10 months 24 days