Label	Element	Value
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents	us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	$ 0
Noncontrolling Interest [Member]
Equity, Including Portion Attributable to Noncontrolling Interest	us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	55,896,000
Equity, Including Portion Attributable to Noncontrolling Interest	us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	0
Adjustments to Additional Paid in Capital, Change In Ownership	osnl_AdjustmentsToAdditionalPaidInCapitalChangeInOwnership	8,898,000
Noncontrolling Interest, Increase from Sale of Parent Equity Interest	us-gaap_NoncontrollingInterestIncreaseFromSaleOfParentEquityInterest	57,256,000
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	us-gaap_ProfitLoss	718,000
Adjustments to Additional Paid in Capital, Allocation to Redeemable Noncontrolling Interest	osnl_AdjustmentsToAdditionalPaidInCapitalAllocationToRedeemableNoncontrollingInterest	10,976,000
Parent [Member]
Equity, Including Portion Attributable to Noncontrolling Interest	us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	281,058,000
Equity, Including Portion Attributable to Noncontrolling Interest	us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	0
Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs	us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts	13,892,000
Other Comprehensive Income (Loss), Net of Tax	us-gaap_OtherComprehensiveIncomeLossNetOfTax	5,981,000
Dividends, Common Stock	us-gaap_DividendsCommonStock	1,764,000
Adjustments to Additional Paid in Capital, Change In Ownership	osnl_AdjustmentsToAdditionalPaidInCapitalChangeInOwnership	(8,898,000)
Stock Issued During Period, Value, New Issues	us-gaap_StockIssuedDuringPeriodValueNewIssues	302,443,000
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	us-gaap_ProfitLoss	(2,812,000)
Retained Earnings [Member]
Equity, Including Portion Attributable to Noncontrolling Interest	us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	0
Equity, Including Portion Attributable to Noncontrolling Interest	us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	(4,576,000)
Dividends, Common Stock	us-gaap_DividendsCommonStock	1,764,000
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	us-gaap_ProfitLoss	(2,812,000)
Additional Paid-in Capital [Member]
Equity, Including Portion Attributable to Noncontrolling Interest	us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	279,350,000
Equity, Including Portion Attributable to Noncontrolling Interest	us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	0
Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs	us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts	13,892,000
Adjustments to Additional Paid in Capital, Change In Ownership	osnl_AdjustmentsToAdditionalPaidInCapitalChangeInOwnership	(8,898,000)
Stock Issued During Period, Value, New Issues	us-gaap_StockIssuedDuringPeriodValueNewIssues	302,140,000
Total Equity, Excluding Redeemable Non Controlling Interest [Member]
Equity, Including Portion Attributable to Noncontrolling Interest	us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	0
Equity, Including Portion Attributable to Noncontrolling Interest	us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	336,954,000
Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs	us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts	13,892,000
Other Comprehensive Income (Loss), Net of Tax	us-gaap_OtherComprehensiveIncomeLossNetOfTax	5,981,000
Dividends, Common Stock	us-gaap_DividendsCommonStock	1,764,000
Adjustments to Additional Paid in Capital, Change In Ownership	osnl_AdjustmentsToAdditionalPaidInCapitalChangeInOwnership	0
Stock Issued During Period, Value, New Issues	us-gaap_StockIssuedDuringPeriodValueNewIssues	302,443,000
Noncontrolling Interest, Increase from Sale of Parent Equity Interest	us-gaap_NoncontrollingInterestIncreaseFromSaleOfParentEquityInterest	57,256,000
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	us-gaap_ProfitLoss	(2,094,000)
Adjustments to Additional Paid in Capital, Allocation to Redeemable Noncontrolling Interest	osnl_AdjustmentsToAdditionalPaidInCapitalAllocationToRedeemableNoncontrollingInterest	10,976,000
AOCI Attributable to Parent [Member]
Equity, Including Portion Attributable to Noncontrolling Interest	us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	5,981,000
Equity, Including Portion Attributable to Noncontrolling Interest	us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	0
Other Comprehensive Income (Loss), Net of Tax	us-gaap_OtherComprehensiveIncomeLossNetOfTax	5,981,000
Common Class S [Member] | Common Stock [Member]
Equity, Including Portion Attributable to Noncontrolling Interest	us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	184,000
Equity, Including Portion Attributable to Noncontrolling Interest	us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	0
Stock Issued During Period, Value, New Issues	us-gaap_StockIssuedDuringPeriodValueNewIssues	184,000
Common Class D [Member] | Common Stock [Member]
Equity, Including Portion Attributable to Noncontrolling Interest	us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	0
Equity, Including Portion Attributable to Noncontrolling Interest	us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	0
Common Class I Shares [Member] | Common Stock [Member]
Equity, Including Portion Attributable to Noncontrolling Interest	us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	0
Equity, Including Portion Attributable to Noncontrolling Interest	us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	119,000
Stock Issued During Period, Value, New Issues	us-gaap_StockIssuedDuringPeriodValueNewIssues	$ 119,000