Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements - Additional Information (Details)

v3.19.1
Fair Value Measurements - Additional Information (Details) - Level 3 [Member]
3 Months Ended 12 Months Ended
Mar. 31, 2019
Dec. 31, 2017
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]    
Fair value interest rate spreads, minimum 1.00% 1.00%
Fair value interest rate spreads, maximum 4.00% 4.00%