Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements - Assets and Liabilities Measured at Fair Value (Details)

v3.19.2
Fair Value Measurements - Assets and Liabilities Measured at Fair Value (Details) - USD ($)
Jun. 30, 2019
Dec. 31, 2018
Dec. 31, 2017
Business Acquisition, Contingent Consideration [Line Items]      
Contingent consideration, fair value $ 0 $ 6,000,000 $ 414,000
Recurring      
Business Acquisition, Contingent Consideration [Line Items]      
Total assets measured at fair value 363,000    
Total liabilities measured at fair value   6,413,000  
Recurring | Level 1      
Business Acquisition, Contingent Consideration [Line Items]      
Total assets measured at fair value 0    
Total liabilities measured at fair value   0  
Recurring | Level 2      
Business Acquisition, Contingent Consideration [Line Items]      
Total assets measured at fair value 363,000    
Total liabilities measured at fair value   413,000  
Recurring | Level 3      
Business Acquisition, Contingent Consideration [Line Items]      
Total assets measured at fair value 0    
Total liabilities measured at fair value   6,000,000  
Recurring | Contingent Consideration | LeaseLabs      
Business Acquisition, Contingent Consideration [Line Items]      
Contingent consideration, fair value   6,000,000  
Recurring | Contingent Consideration | LeaseLabs | Level 1      
Business Acquisition, Contingent Consideration [Line Items]      
Contingent consideration, fair value   0  
Recurring | Contingent Consideration | LeaseLabs | Level 2      
Business Acquisition, Contingent Consideration [Line Items]      
Contingent consideration, fair value   0  
Recurring | Contingent Consideration | LeaseLabs | Level 3      
Business Acquisition, Contingent Consideration [Line Items]      
Contingent consideration, fair value   6,000,000  
Recurring | Interest rate swap agreements      
Business Acquisition, Contingent Consideration [Line Items]      
Derivative asset, fair value 246,000 923,000  
Derivative liability, fair value 2,469,000 413,000  
Recurring | Interest rate swap agreements | Level 1      
Business Acquisition, Contingent Consideration [Line Items]      
Derivative asset, fair value 0 0  
Derivative liability, fair value 0 0  
Recurring | Interest rate swap agreements | Level 2      
Business Acquisition, Contingent Consideration [Line Items]      
Derivative asset, fair value 246,000 923,000  
Derivative liability, fair value 2,469,000 413,000  
Recurring | Interest rate swap agreements | Level 3      
Business Acquisition, Contingent Consideration [Line Items]      
Derivative asset, fair value 0 0  
Derivative liability, fair value 0 $ 0  
Recurring | Foreign exchange currency contracts      
Business Acquisition, Contingent Consideration [Line Items]      
Derivative asset, fair value 117,000    
Recurring | Foreign exchange currency contracts | Level 2      
Business Acquisition, Contingent Consideration [Line Items]      
Derivative asset, fair value $ 117,000