Note 6. Acquisition (Details) - USD ($) $ in Thousands	1 Months Ended	2 Months Ended	3 Months Ended		6 Months Ended
	Apr. 30, 2015	Jun. 30, 2015	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Goodwill		$ 56,452	$ 56,452		$ 56,452		$ 50,318
TOTAL REVENUES			133,105	$ 136,019	267,370	$ 277,091
Net income (loss)			$ 5,156	$ 3,880	$ 10,487	$ 7,885
GAF Acquiree Member
Business Combination, Step Acquisition, Equity Interest in Acquiree, Percentage	40.00%
Business Combination, Step Acquisition, Equity Interest in Acquiree, Including Subsequent Acquisition, Percentage	80.00%
Business Combination, Step Acquisition, Percentage of Interest Acquired	40.00%
Payments to Acquire Businesses, Gross	$ 325
Business Combination, Consideration Transferred, Other	1,195
Equity Method Investments	1,908
Business Combination, Step Acquisition, Equity Interest in Acquiree, Remeasurement Loss	692
Business Combination, Step Acquisition, Equity Interest in Acquiree, Fair Value	1,216
Nonmonetary Transaction, Gain (Loss) Recognized on Transfer	1,195
Goodwill	6,134
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill	5,500
Business Combination, Consideration Transferred	1,520
Business Combination, Acquisition of Less than 100 Percent, Noncontrolling Interest, Fair Value	608
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net	(2,790)
TOTAL REVENUES		1,741
Net income (loss)		$ 300
GAF Acquiree Member | Accounts Payable and Accrued Liabilities | Fair Value, Inputs, Level 3
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Contingent Liability	1,000
GAF Acquiree Member | Other Income
Business Combination, Step Acquisition, Total Gain (Loss)	$ 503