Unsecured Lines of Credit Payable - Narrative (Details) | 3 Months Ended | | | |
Mar. 31, 2018USD ($)extension_option | Mar. 29, 2018USD ($) | Jul. 22, 2016USD ($) | Sep. 15, 2015USD ($) |
Interest Rate Swap [Member] | | | | |
Line of Credit Facility [Line Items] | | | | |
Derivative, notional amount | $ 400,000,000 | | | |
LIBOR [Member] | | | | |
Line of Credit Facility [Line Items] | | | | |
Debt instrument variable rate (percent) | 1.88% | | | |
Line of Credit | | | | |
Line of Credit Facility [Line Items] | | | | |
Commitment fee (percent) | 0.20% | | | |
Interest rate during period (percent) | 1.00% | | | |
Line of Credit | Minimum [Member] | | | | |
Line of Credit Facility [Line Items] | | | | |
Commitment fee (percent) | 0.10% | | | |
Line of Credit | Maximum [Member] | | | | |
Line of Credit Facility [Line Items] | | | | |
Commitment fee (percent) | 0.30% | | | |
Line of Credit | LIBOR [Member] | | | | |
Line of Credit Facility [Line Items] | | | | |
Basis spread on variable rate (percent) | 1.00% | | | |
Line of Credit | LIBOR [Member] | Minimum [Member] | | | | |
Line of Credit Facility [Line Items] | | | | |
Basis spread on variable rate (percent) | 0.775% | | | |
Line of Credit | LIBOR [Member] | Maximum [Member] | | | | |
Line of Credit Facility [Line Items] | | | | |
Basis spread on variable rate (percent) | 1.55% | | | |
Line of Credit | Base Rate [Member] | Minimum [Member] | | | | |
Line of Credit Facility [Line Items] | | | | |
Basis spread on variable rate (percent) | 0.00% | | | |
Line of Credit | Base Rate [Member] | Maximum [Member] | | | | |
Line of Credit Facility [Line Items] | | | | |
Basis spread on variable rate (percent) | 0.55% | | | |
Line of Credit | Federal Funds Effective Swap Rate [Member] | | | | |
Line of Credit Facility [Line Items] | | | | |
Basis spread on variable rate (percent) | 0.50% | | | |
2015 Term Loan [Member] | Interest Rate Swap [Member] | | | | |
Line of Credit Facility [Line Items] | | | | |
Derivative, notional amount | | | | $ 150,000,000 |
Derivative, fixed interest rate (percent) | | | | 2.72% |
2018 Term Loan [Member] | | | | |
Line of Credit Facility [Line Items] | | | | |
Debt instrument, face amount | | $ 250,000,000 | | |
2018 Term Loan A [Member] | Interest Rate Swap [Member] | | | | |
Line of Credit Facility [Line Items] | | | | |
Derivative, notional amount | | $ 150,000,000 | $ 150,000,000 | |
Derivative, fixed interest rate (percent) | | 2.31% | | |
2018 Term Loan A [Member] | LIBOR [Member] | Minimum [Member] | | | | |
Line of Credit Facility [Line Items] | | | | |
Basis spread on variable rate (percent) | 0.85% | | | |
2018 Term Loan A [Member] | LIBOR [Member] | Maximum [Member] | | | | |
Line of Credit Facility [Line Items] | | | | |
Basis spread on variable rate (percent) | 1.75% | | | |
2018 Term Loan A [Member] | Base Rate [Member] | Minimum [Member] | | | | |
Line of Credit Facility [Line Items] | | | | |
Basis spread on variable rate (percent) | 0.00% | | | |
2018 Term Loan A [Member] | Base Rate [Member] | Maximum [Member] | | | | |
Line of Credit Facility [Line Items] | | | | |
Basis spread on variable rate (percent) | 0.75% | | | |
2018 Term Loan B [Member] | | | | |
Line of Credit Facility [Line Items] | | | | |
Derivative, notional amount | | $ 100,000,000 | | |
2018 Term Loan B [Member] | Interest Rate Swap [Member] | | | | |
Line of Credit Facility [Line Items] | | | | |
Derivative, notional amount | | $ 100,000,000 | | |
Derivative, fixed interest rate (percent) | | 3.71% | | |
Credit facility 2018 [Member] | | | | |
Line of Credit Facility [Line Items] | | | | |
Committed capacity | $ 1,500,000,000 | | | |
Credit facility 2018 [Member] | Line of Credit | | | | |
Line of Credit Facility [Line Items] | | | | |
Committed capacity | $ 700,000,000 | | | |
Debt instrument, term | 4 years | | | |
Debt instrument, maturity date | Mar. 29, 2022 | | | |
Number of extensions allowed | extension_option | 2 | | | |
Term of extension | 6 months | | | |
Credit facility 2018 [Member] | 2015 Term Loan [Member] | | | | |
Line of Credit Facility [Line Items] | | | | |
Debt instrument, face amount | $ 150,000,000 | | | |
Credit facility 2018 [Member] | 2018 Term Loan [Member] | | | | |
Line of Credit Facility [Line Items] | | | | |
Debt instrument, face amount | 250,000,000 | | | |
Credit facility 2018 [Member] | 2018 Term Loan A [Member] | | | | |
Line of Credit Facility [Line Items] | | | | |
Debt instrument, face amount | $ 150,000,000 | | | |
Credit facility 2018 [Member] | 2018 Term Loan A [Member] | LIBOR [Member] | | | | |
Line of Credit Facility [Line Items] | | | | |
Basis spread on variable rate (percent) | 1.10% | | | |
Credit facility 2018 [Member] | 2018 Term Loan B [Member] | | | | |
Line of Credit Facility [Line Items] | | | | |
Proceeds from term loan | $ 100,000,000 | | | |
Credit facility 2015 [Member] | Line of Credit | | | | |
Line of Credit Facility [Line Items] | | | | |
Committed capacity | $ 600,000,000 | | | |
Debt instrument, maturity date | Jun. 22, 2019 | | | |