Earnings per Share (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Numerator [Abstract]
Net income attributable to controlling interest	$ 2,292	$ 1,916	$ 29,201	$ 25,958
Denominator [Abstract]
Denominator for basic earnings per share (in shares)	22,943	22,830	22,930	22,813
Effect of dilutive securities [Abstract]
Employee stock options and restricted stock units (in shares)	114	167	124	180
Supplemental Executive Retirement Plan (in shares)	64	112	64	110
Denominator for diluted earnings per share (in shares)	23,121	23,109	23,118	23,103